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Building a Solar-powered Bristlebot

Adding solar panels to a brushbot project gives a new twist to an intermediate robotics building activity, but does it offer more power? With this clever build and a kit from the Science Buddies Store, it was easy to put that question to the test!

Advanced Bristlebot Solar-Powered Kit and Hands-on Robotics Project - multiple imagesAdvanced Bristlebot Solar-Powered Kit and Hands-on Robotics Project - bear head or googly eyes

After a successful series of building robots using Science Buddies procedures, we recently gave the Solar-powered Bristlebot a try. This bot is very closely related to the Light-tracking Bristlebot we built a few years back. Both of these bots can be built using the Advanced Bristlebot Kit from the Science Buddies Store, a fact that makes gathering the right specialty/electronics supplies really easy—just open the box!

My student decided to build this robot over spring break. We didn't need to do this hands-on science activity for school. We didn't need to formally track or test or measure. The focus was on the building, on the experience of plugging things into the breadboard appropriately. As a parent, this kind of casual at-home science and engineering moment is priceless.

Because our goal was on building, my role in the process was reading the directions out loud. He did all the assembly, all the breadboard hole-counting, tinkering, adjusting, taping, and customizing. That I had not been quite on top of things enough to have the right additional required elements gathered and on hand when the urge to build this bot struck meant I couldn't quite find the double-sided foam tape. He first improvised by making loops of clear tape to hold the small vibrating motors in place, but ultimately, he moved on to electrical tape. (We have lots of that!)

When the build was finished, we didn't have googly eyes, which some consider a "must" for their bots. But the impulse to customize his bot and give it added character was not lost. The head from a toy figurine made a perfect masthead for his bot, and, not shown here, a tiger figurine even got added at one point to ride on the bot!

As for the exploration of solar power... going outside to see if the motors would start spinning in the sun was exciting and rewarding.

This is a great and easy-to-follow project for at-home electronics and robotics fun!

Home Adventures in Robotics

For a look at some of our ther robotics-building experiences, and for related projects and activities that are fun for kids to do at home (with you or alone), see the following:

(Hint: The list above may be very helpful for summer activity planning!)



We go DIY with molecular gastronomy and family science as we make our own popping boba using the Spherification Kit from the Science Buddies Store.

Spherification popping boba

When it is hot outside, my kids love to pit stop at the nearby frozen yogurt shop where they can swirl frozen yogurt into an oversized paper bowl and load it up with toppings of their choice. Favorite toppings vary, but one kid's heaping concoction always includes little slippery, fruit-flavored balls—popping boba.

Popping boba are similar to the boba found in bubble (or boba) tea, but the small spheres have a very thin exterior skin, are filled with juice (or something similar), and "pop" in your mouth when you squeeze or bite them. In my house, the fascination with popping boba is so strong, and the availability at the yogurt shop so variable, that we ended up ordering popping boba in bulk.

We now have close to thirty pounds of the little liquid-filled balls sitting in giant plastic containers at the house!

Cool Home Science

Just about the time I was unpacking all that boba, the Spherification kit became available in the Science Buddies Store. I knew the molecular gastronomy spherification process is used in a human biology project that lets students explore how blood clots. In that science project, students use spherification to simulate and explore the clotting process—and to better understand what happens when clotting doesn't work properly. But I hadn't realized when reviewing the project on hemophilia and clotting that the same process used in the Science Buddies project to help students better understand a core biological process is actually a technique more commonly used to make something edible—tasty treats referred to as "spherification caviar" that can be eaten alone, added to desserts, or even used in drinks.

From juice-filled spherification caviar to spheres of sauces, honey, and even solid foods, many cooks use spherification to add something flavor-filled and unexpected to their dishes.

As I read the product information describing the Spherification kit and took a look at the brand new Serving Spheres for Supper: Use Molecular Gastronomy to Change the Shape of Your Food project that involves spherification, I realized that what students make in the project is very, very similar to popping boba.

Making Boba

My fifth grade student was excited to try making boba at home. We didn't do the spherification project as a science fair experiment, so we were not running trials based on the amount of sodium citrate added to our liquid solution (our "filling"). Even so, we knew from talking about the spherification project and process that not all liquids respond to spherification the same, in part because of their pH. Since fresh squeezed orange juice is what my student wanted to try for our foray into boba making, pH was a definite concern. The typical pH of orange juice is low, around 3.5, which makes it fairly acidic. (Tip: research the pH of other juices and drinks with your kids to find out how they compare! You can learn more about the pH scale here.)

For the spherification process to work with orange juice, we knew that we might need to lower the acidity of the juice by adding small amounts of sodium citrate to the mixture and seeing how well the spheres formed. (We also knew that even if spheres didn't form, we could inject strings of solution into the calcium bath and fish out something similar to gummy worms! Nothing you drop into the calcium bath is really going to be wasted... it just may or may not make a sphere.)

With that in mind, we got out our ingredients, opened the Science Buddies project up on a tablet for reference, and got down to some serious boba-making business.

Sizing Boba

Our spherification attempts were lots of fun, and as is often the case with home science activities, we tried a number of things, observed what happened with each change we made, and branched out and tried some unexpected things as well. We were amazed to see that dropping a drop of juice from the syringe into the calcium bath almost instantly formed a sphere. Excited by our immediate spherical success, we dropped several in (one by one), waited the 60 seconds, fished them out, and put them to the taste test. Because we hadn't rinsed them, they were a bit saltier than we expected (but still totally safe to eat). But, they worked! They were very much like popping boba—and filled with fresh orange juice. Very cool!

They were tiny.

Seriously tiny.

But they were juice-filled spheres, and they did pop in our mouths.

Using the syringe, we made several bowls of homemade popping boba. We played around with our solution, experimenting to see what difference differing amounts of sodium citrate might make. We made some gummy worms.

And then we got creative. The biggest disappointment for us was the small size of the caviar spheres. How could we make them bigger? What would happen if we dropped our juice into the mix by something larger, like a very small measuring spoon? We experimented with several differently sized spoons and techniques, and, voila, we ended up with larger boba.

The process was a huge hit, and we will definitely try spherification again. We have other questions we want to answer, and using a different kind of juice or drink will let us see how the process changes based on what food or liquid we use to fill our spheres.

Try It at Home

If you have kids who love kitchen science or who are enamored with popping boba, spherification is definitely something to try at home. The kit from the Science Buddies Store contains enough materials to make quite a bit of boba (or other spherification caviar), so this is a project you can pull out on a rainy afternoon, with a group of kids after school, or any time. You will need some regular household supplies on hand, including bowls, access to a blender, spoons, and your filling (e.g., juice), but the process is fast, and cleanup is easy.

Here are a few tips and pointers, based on our experience, for home experimentation:

  • Your juice (or filling) should be refrigerator cold before you begin. Many spherification recipes also suggest refrigerating the sodium alginate solution for several hours (to remove air bubbles). If you encounter problems making your boba, keep this in mind as something to try.
  • Mixing up the juice with the sodium alginate took some doing. We tried a handheld milk frother rather than a blender, for convenience. It may not have been powerful enough, and the sodium alginate did want to clump in the liquid rather than mix. Keep at it! You want to get the solution as thoroughly mixed as you can. If you have an immersion blender, you may find it just the right tool for the task!
  • Fishing the spheres, especially the super tiny ones, from our calcium bath was not easy using a regular spoon. If you have a small strainer-type spoon, or a spoon with very small slots or holes, you may find it easier to fish the balls out.
  • Rinsing the balls before eating them helps remove the salty taste.
  • Experiment with the angle at which you hold the syringe and how quickly you release the solution into the bath (or how forcefully you push the plunger).
  • If you decide to try larger spheres, experiment with the speed at which you drop the solution into the bath.
  • Keep in mind that boba made this way should be eaten shortly after making them. They will continue to harden!

If your home trials lead your kids to ask further questions about boba and how companies make lots of boba, you may enjoy watching a video like this one, which shows a tool that can be used to create uniform spherification caviar in batches (see screenshot below). You may also want to look around online at some of the many cool and exciting recipe ideas you will find for spherification caviar. Juice is only the beginning!

Spherification caviar maker / screenshot from video

Reverse Spherification

In your research on spherification and molecular gastronomy, you will also see "reverse spherification" mentioned and noted in some recipes. This is a process used when trying to encapsulate foods that contain calcium. Stay tuned for a Science Buddies project on making "yogurt ravioli" using reverse spherification!



From Wooden Train to the Magic of Maglev

For a third grade student with an interest in science and pinewood derby cars, the Maglev Train project combined a fun DIY activity with engaging science. A levitating train is science kids can see!

Family Maglev Train Success Story

Family Science is Fun!

Alex and Lisa, pictured above, built and explored the Magic Bullet Train kit from the Science Buddies Store. Alex's train turned out great, and we love the gold paint! For more family science inspiration featuring the maglev train kit and project, see Magic Train Puts Kids on Track with Physics of Magnetism.

The science of magnetism often has strong pull with elementary school students. Couple a seemingly innate interest in magnets with an interest in trains, and you have the makings of a winning science project for school or a creative science exploration for a rainy day at home.

In preparation for spending summer time with her eight year old stepson, Lisa scoped out a number of projects and activities that would be both fun and educational. After spotting mention of the Magic Bullet Train project at Facebook, Lisa checked out the project at Science Buddies and quickly added it to her list of growing list of possibilities.

"I thought that Alex would enjoy it because he is very interested in science. He has also done pinewood derby cars with the Boy Scouts, so I knew he would be familiar with the shaping and painting skills we would need to make the train."

Along with supplies for other summer projects, Lisa ordered the Magic Bullet Train kit from the Science Buddies Store. When Alex arrived for a summer visit, she had plenty of great "to do" options to show him, from a pyramid excavation kit and a hydraulic crane set to snap circuits and a laser maze. The bullet train science kit was an immediate hit.

"Alex was excited about this kit right away. He knew that he wanted his train to have the shape of the one shown on the side of the Maglev train box," says Lisa. With a plan in mind for customizing his train, Lisa and Alex headed to the store to buy sandpaper, primer, and paint.

Because the project involves both designing and shaping a small train from a block of wood, assembling the magnetic railway, and then doing hands-on testing to see the train in action, the Magic Bullet Train project is one that kids can work on over several days. For many kids, the creative energy spent fashioning and personalizing the train makes them even more invested in the project.

"Alex worked on shaping the train with the sandpaper for a little while every day for about a week," says Lisa. "He was excited when it was finally time to paint it." Using blue, gold, and white paint he had picked out, Alex transformed his shaped wooden train into a model of a real train with gold sides, a blue roof, and a painted windshield and windows.

Throughout the project, Lisa says she and Alex talked about the science behind the project and behind real-world Maglev trains. "We discussed what 'maglev' means," says Lisa, "and talked about magnets and the meaning of the word levitation."

When the train and track were complete, Alex got the chance to see the train glide across the rails—without touching them—because of magnetic levitation.

As both a teacher and a parent, Lisa believes doing hands-on science with kids is important. "It's a great way to bond with kids, to explore a new idea together, and to get kids talking about what they think. I love to hear kids explain how they think the world works."

As a third grader, Alex is interested in science, the Civil War, rocks, and Dr. Who. Right now, he looks ahead to the future and says he wants to study geology or physics in college.

His hand-painted Maglev train will always be a reminder of a summer with his family—and of how much fun science can be!

Science Buddies in Action

Read more stories about student, teacher, and family success with hands-on science projects and activities. Have a story of your own? We would love to hear about your experience!



Brushbot from the Bristlebot robotics kit at Science Buddies
Above: The Brushbot is one of the three robots kids can build using the Bristlebot Kit from the Science Buddies Store.

A brand new Bristlebot Kit launched today in the Science Buddies Store. With this new kit, students can experiment with three styles of introductory robots and learn more about robotics engineering. The kit has been specially designed to make building the robots easier for students to do independently—and fun!

The new Bristlebot Kit contains components for use with several Science Buddies Project Ideas and activities, including:

For more information about introducing robotics engineering projects to K-12 students at school or at home, see the following:

Support for resources and Project Ideas in robotics is provided by Northrop Grumman, Symantec Corporation, and the Best Buy Foundation.



Chemistry titration project (and science kit) to investigate and compare quantities of Vitamin C in juice.

To investigate the science question above regarding quantities of Vitamin C in different kinds of juices or drinks, see the following resources and projects:

For other Science Buddies Project Ideas involving titration, see:

(Note: The projects above can be done using the Orange Juice titration kit from the Science Buddies Store.)



Improvements in the Science Buddies Crystal Radio Kit make building a crystal radio a science project students may enjoy for the school science fair or just as an independent electronics experiment—no batteries required! Our scientists have worked to improve the kit and procedure for the best student science experience.

Crystal Radio Science Project Photos
Above: photos taken during a student crystal radio project experiment using the Build a Crystal Radio kit from the Science Buddies Store.

The crystal radio project was one of our first electronics projects beyond the color-coded snap-together circuits that crop up in many households when kids are little. My oldest student did the pencil resistors project as his very first school science fair project. He followed that up the next year with the Build Your Own Crystal Radio experiment. (Note: Both of these projects are ones he selected because they appeared in the list of recommendations after he used the Topic Selection Wizard.)

A Classic Experiment

The crystal radio project is frequently among the most popular electronics explorations at Science Buddies. It is, after all, a classic introductory electronics project. Plus, this is a hands-on science exploration that gets bonus points for novelty and wow-factor. A radio you can listen to without a battery? And, these days you might add, without a solar panel?

That's pretty nifty electronics for many kids, and after going through the steps of building something hands-on, you get to put it to the test and see what stations you can tune in. Any confusion over why this radio is called a "crystal" radio is quickly cleared up during background research. (Hint: "crystal" is related to the fact that a crystal diode, often a germanium diode, is at the heart of the circuit. Learn more about the history of crystal radio sets in this interview.)

There are many, many ways to assemble a crystal radio. The year my son did the project, the kit at Science Buddies was much different than the kit now sold in the Science Buddies Store. The project, too, was older and did not contain the abundance of photos to help guide the build the way the updated Project Idea does.

A New and Improved Kit and Scientist-guided Procedure

This year, the Crystal Radio Kit sold in the Science Buddies Store was updated to address some common stumbling blocks and user feedback from students and families who had built crystal radios using the earlier kit, materials they gathered independently, or other novelty or toy-store science kits. Along with the changes to the kit materials, the corresponding Project Idea and step-by-step procedure got a snazzy face lift. As the new kit made its way into the Science Buddies Store, we put a few of the procedural steps in action to see how the new kit and the old kit compare.

When my student built his crystal radio for the science fair, he ran into a bit of trouble making "taps," a fairly common approach in building a crystal radio. (After making a series of "taps" along the coil, you clip alligator clips to the taps to see what stations you can hear.) Unfortunately, to make those taps, you have to strip the coating from looped sections of wire after every so many wraps around the coil—while keeping the coil nice, tight, and in place. Depending on your materials, this procedure can work, but we had trouble.

My student ended up using a hodgepodge approach and breaking the wire at the loops, stripping the ends, and twisting them to form the taps—no loops in sight. It was an important learning step for my student because we had to troubleshoot to find a way, with the materials we had, to do what we needed to do. In trying to sort out how to rig another portion of the circuit, he learned a lot, too, about where the current goes and whether or not it matters if things are clipped together—or just touching.

In the end, his crystal radio worked. He dropped a ground wire out the bathroom window, tied it to a pole next to the house, and strung antenna throughout the house at ceiling level. Then he sat in the hallway, ceramic ear piece in his ear, and he tried out his taps to see what stations he could hear. The stations he picked up with his indoor antenna are not ones that will replace a stash of MP3s, but the experiment was a success—and a winner at the school science fair, too.

The old crystal radio kit worked, and he had a great time with the project. But building the crystal radio using the new kit was even easier!

A Classic Project Made Even Better

The entire project has been rewritten to use a new set of supplies that remove the hurdles and headaches that many students (and sometimes their parents) run into when trying a crystal radio project. In the new kit, there are no taps. Instead, the kit uses a thinner gauge wire, and once the coil is wrapped, students use a brass tuning rod to search for stations. Very cool!

Say goodbye to the ear piece, too. While an ear piece currently still comes in the Crystal Radio kit, the new kit contains a speaker/amplifier element that lets students hear stations much more easily.

Not only are the materials in the updated kit better, and higher quality than the ones you may find in the kinds of crystal radio kits in toy stores, but the revised procedure is loaded with awesome close-up photos that show the build, step by step. This is a great, easy-to-follow, electronics project, and the kit makes the process straightforward and hassle-free. (As a parent, I speak from experience! I took a printout of the original procedure to a local electronics store to pick up an extra spool of wire, got assistance from a clerk, and still came home with exactly the wrong kind of wire. Having the right materials in the box may make a big difference in how smoothly a student science project goes!)

If your student is looking for a fun science project or a great at-home project for spring break or summer building, consider the Crystal Radio. It's a great stepping stone into the next level of electronics!



Renewable energy is hiding in places you might not think to look! For a glimpse into the future of power generation, experiment with a microbial fuel cell.

By Kim Mullin

Microbial fuel cell hacker board / Energy science kit

Microbial Fuel Cells—Building Your Own Alternative Energy Experiment

After assembling your microbial fuel cell using a kit (available in the Science Buddies Store), connect the fuel cell's hacker board, shown above. Within 3-10 days, the hacker board should begin blinking, though you will start taking measurements right away!

In addition to the microbial fuel cell projects listed, students interested in alternative energy projects might explore:

Ask anyone about sources of renewable energy, and they are likely to mention solar power, wind power, or perhaps even geothermal power. Hydro (or water) power, too, may come up, but when you talk about water as a renewable energy source, you probably are talking about energy harnessed from falling or running water.

But what about the dirty water running through our underground sewage pipes? What if a wastewater treatment plant could power itself with the very water that it is supposed to clean?

Beyond Sun and Wind

The idea of producing energy from dirty water isn't as far-fetched as it sounds. Thanks to something called a microbial fuel cell, extracting energy from microbes such as bacteria is possible. Why? Because some types of bacteria produce electrons when they feed on the nutrients found in places such as dirty water or soil—both of which are easy to find! In a microbial fuel cell, these electrons can be captured by electrodes and used as a power source.

You may be wondering what sorts of "nutrients" can be found in dirty water and soil. After all, humans depend on fresh fruits, vegetables, and proteins for the vitamins and minerals that help us thrive. However, some types of bacteria can live on compounds that our bodies treat as waste. For example, the urine that we flush down the toilet is full of nitrogen, and nitrogen is part of a healthy diet for some types of bacteria.

Harnessing the Power of Bacteria

Scientists discovered electricity-producing bacteria in the early 1900s, but recent interest in renewable energy has increased research in this area. To make microbial fuel cells a viable renewable power source, one important question that scientists must answer is how to best maximize the amount of electricity that they can produce.

With the Science Buddies Project Ideas below, you can be a renewable energy scientist. Try any of these projects to get started:

Powering the Future

While you shouldn't expect to be recharging your cell phone with a microbial fuel cell next year, it is possible that one day this technology will be as common as solar panels. Will you be among the scientists who explore innovative ways to keep up with our energy needs?

Microbial fuel cell alternative energy kit from Science Buddies Store

Support for this Project Idea was provided, in part, by PG&E



A biotechnology kit from Bio-Rad Laboratories introduces young scientists to the world of biochemistry. In this fun science activity, kids can extract their own DNA, examine it without a microscope, and create a pendant containing their DNA—the ultimate item for cool-but-geeky show and tell!
By Kim Mullin

DNA activity / Genes in a Bottle biotechnology exploration for students
With a fun science kit from Bio-Rad Laboratories, you and your students can extract DNA—and then preserve it in a cool necklace. This is hands-on science that is sure to be a hit at the next show and tell!
Calling All DNA Detectives!

You may know that DNA is found in almost every cell of your body, but did you know that it is possible to see your DNA without a microscope? You don't need to be in a fancy scientific lab to become a DNA detective! Exploring the fascinating world of DNA is simple and quick with Science Buddies' "Discovering DNA: Do Your Cheek Cells & a Strawberry Both Have DNA?" Project Idea and the Genes in a BottleTM kit from Bio-Rad Laboratories!

What is DNA?

DNA, or deoxyribonucleic acid, is the blueprint for everything that happens inside the cell of an organism, and each cell in an organism has a copy of the same set of instructions. The entire set of instructions that make you you is called your genome.

Scientists study DNA for many reasons. They can figure out how the instructions stored in DNA help your body to function properly. They can use DNA to decide what new medicines are needed to treat a disease. They can figure out the suspect of a crime. They can even use ancient DNA to reconstruct evolutionary histories!

See Your Own DNA!

How do scientists get DNA from a cell so that they can study it? They use a process called a DNA extraction. Although this may sound like something best left to professionals, DNA extraction is simple enough that you can try it out at home! Following the simple steps outlined in the Discovering DNA: Do Your Cheek Cells & a Strawberry Both Have DNA? Project Idea, you can extract DNA from your own cheek and take a look.

The Genes in a Bottle kit contains everything you need for this science activity. The kit also comes with a pendant and instructions for coloring your precipitated DNA. After you are finished with the extraction, you can make a unique helix keepsake filled with strands of your own DNA to show off to your friends and family—proof positive that even kids can be biochemists!

Where Else Can You Find DNA?

Once you see your own DNA, you may wonder about DNA and other living things. If your cells have DNA that provides the instructions for creating your eye and hair color, then what about the eye and fur color of other animals? Or the shapes and colors of leaves and plants? With a bit of human cheek DNA extraction experience hanging around your neck, you can move on to extracting DNA from a strawberry to see if plants also have DNA. Will the DNA appear the same?

Once you've analyzed the DNA from a strawberry, why stop? Check for DNA in other fruits, vegetables, and grains. An onion can be an eye-opening next step! Can you extract more DNA from some items than from others? With your new DNA detective skills, you can find out!

Science Buddies Project Ideas in Biotechnology Techniques are sponsored by support from Bio-Rad Laboratories and its Biotechnology Explorer program.



The Call of the Crystal Radio

Ask an engineer if she has ever built a crystal radio, and chances are you will get a story—one with all the makings of a classic when it comes to garage engineering and adolescence. Students often build a crystal radio as a first step in engineering and electronics—or as a middle school science fair project. If they have questions or need assistance troubleshooting their "set," they may be lucky enough to get assistance from Rick Marz, a seasoned engineer with an enduring affinity for crystal sets and a commitment to passing his expertise on to students.

Crystal Radio Set diagram from 1920s
The Golden Age of Radio

The diagram above is from a 1920s publication distributed to teach the general public how to make their own simple and inexpensive radio. Using wire and a common cardboard container, students can create a similar crystal set as a science project. For aspiring student engineers, a crystal radio exploration is a great hands-on project and may be a stepping stone into other electronics and engineering investigations. A convenient Science Buddies kit is available for this science project!

Crystal Radio Science Project Kit

Building Your First Crystal Set is Just the Beginning

Once your crystal radio is built, put it to the test! There are many variables you can manipulate to gain a better understanding of how the receiver works and how sound waves from the AM spectrum are picked up by your set. Students looking to extend a crystal radio exploration might consider adding a capacitator. What advantages will this bring?

AM Radio Transmitter science project kit

Sending and Receiving

Students interested in radio may also enjoy building and testing their own AM radio transmitter based on the "Make Your Own Low-Power AM Radio Transmitter" Project Idea.

Have you built a crystal radio or the low-power AM transmitter? Share your photos with the Science Buddies community!

One of Science Buddies' perennially popular electronics investigations is the "Crystal Radio" project. The allure of using a few basic materials to create a functional AM radio that requires no electricity or power supply is irresistible for many student engineers. This isn't simply a rote exercise in wiring a simple circuit to see a light bulb go on and off. Instead, by wrapping a canister (similar to one left over from a month's worth of oatmeal) with wire and completing a circuit that uses both a resistor and a small diode, you can create a basic AM radio.

Building a crystal radio set is a project that taps a young engineer's DIY love of hands-on wiring and offers a functional product in the end—a classic win-win. Granted, you won't toss your stereo or MP3 player out the window in favor of a crystal radio. But, if constructed properly, you can tune in to local AM radio stations as a result of learning more about modulation, radio waves, alternating (AC) and direct (DC) currents, diodes, and semiconductors.

A Hallmark of Engineering Exploration

Many engineers have a soft spot for crystal radio science projects. Whether they recall wiring their own crystal radio set and seeing their first semiconductor in action, or, like Rick Marz, grew up in a time when radio was a primary source of entertainment and hands-on engineering, crystal radios may be a rite of passage in the field of electronics.

Retired after forty-five years in the semiconductor business, Rick is a long-time volunteer at Science Buddies and part of the team of volunteer Experts who help assist students and parents in the Ask an Expert (AAE) forums. As an Expert at AAE, Rick has helped hundreds of students with questions about their electronics and engineering projects, including popular projects like the "Electrolyte Challenge," "Spin Right 'Round with this Simple Electric Motor," "Shaking Up Some Energy," "Is This Connected to That?" and "Build Your Own Crystal Radio."

Rick enjoys helping students with a wide range of electronics and engineering questions in the forums, but he has a particular fondness for crystal radio investigations and a history with crystal radio that goes back more than fifty years. By his own estimate, Rick says he is one of the last of a small group of crystal radio experts.

Witness to an Epoch

Having spent forty-five years in the semiconductor business, Rick has been a part of the industry from its beginnings in the 1960s. "At a recent semiconductor alumni dinner," says Rick, "we calculated that we had witnessed 99.8% of the growth of the entire semiconductor, computer and communication industry during our career." As it turns out, his interest began well before there even was an industry.

"Maybe I exaggerated a bit when I claimed to be the 'last of a small group' of crystal set experts, but I don't think I'm too far off," says Rick. "I grew up before television existed, and the radio in every home was the sole source of connected entertainment and the source of much of the outside information we received." For today's students, imagining the world before smart phones, MP3 players, and always-connected devices is often difficult; imagining the realities of life before TV may be even more unfathomable. But TVs didn't become staple items in most U.S. households until the mid-1950s (or later). Prior to that, the radio took center stage as both a pivotal source of information and a beacon for family entertainment. The radio was so central to American life that the period between the 1920s and 1950s is referred to as the Golden Age of Radio.

"The radio was a focal point in every family living room," recalls the engineer. "Music, fictional characters and stories, serial adventures, comedy, and world news on the radio were an important part of growing up," says Rick. "I still remember hours of listening to shows in the darkened living rooms of my grandparents' and parents' houses."

Childhood Curiosity

Rick traces his interest in electronics to an initial curiosity about radio in general. "My interest in radio, and what made it work, started at an early age, probably around 7 or 8." Not only was the radio a prominent device in his house, but the radio was also tied to family history for Rick. "I had heard stories from my grandparents that, as a child, my father constructed many crystal sets of his own in the 1930's using wooden pencils. I was fascinated and soon started to build similar radios using a pencil as the coil form and locating the 'cat's whisker' galena crystal detector at the end of the pencil where the eraser was. A suitable antenna and ground completed a working receiver."

Those pencil-based receivers were among the first Rick explored in a series of crystal sets that spanned many years. "I can't remember my first crystal set exactly, although I do recall that it used the galena crystal and a coil wound on a cardboard tube from a roll of toilet paper." Once completed, tested, and evaluated by the young engineer, those first sets were upcycled and reused. A collection of completed sets wasn't an option. "One of the things you did to build your second radio," explains Rick, "was to cannibalize the first."

Tuning In

In his mid-western hometown, there were only four AM radio stations, and he needed earphones to pick up the faint signals transmitted, but it was enough. He was hooked. His early crystal radio experiments fueled an interest Rick satisfied by building hundreds of crystal radio variations through the years, a number he says is not an exaggeration. Supplementing his burgeoning interest in engineering was the fact that crystal radio construction was a common science exploration for kids. "During that period, crystal sets were important chapters in Cub Scout construction projects," recalls Rick. "You could buy the familiar parts like the PhilmoreTM galena crystal/whisker assembly in hardware and department stores," he says, adding that even "the comic books of the time always had a page or two of ads for crystal set kits."

Always on the lookout for ways to extend, modify, or innovate upon the core concept of a crystal radio set, Rick says he built some models based on "inspiration from the regular tech magazines of the day, Popular Science, Science and Mechanics, Popular Mechanics, etc." In other models, Rick tested out his own ideas for ways to enhance or improve performance. "A lot of component substitution went hand-in-hand with what I thought must be R&D at the time," notes Rick. "There were very few options to building a basic crystal set, so most of the variants were in coil design/construction and antenna/ground choices." For a young engineer, the quest to find new materials that might work was part of the challenge and part of the fun. "I remember visiting radio and TV repair shops and asking to go through their discards looking for usable components."

No matter how many sets he built, the allure of a better set persisted. Crystal radio gets its name from the use of the early galena crystal, but as new and alternative materials became more available, Rick was able to extend his electronics experiments and enjoy the benefits of advancing technology—at a price. He remembers buying his first germanium transistor in 1956, a Raytheon CK722. "I was 12 years old, and the transistor cost over $7. A fortune at that time. Half a summer of savings."

Once you had a new part, you put it to use, says Rick. "By the mid 1950's, early germanium diodes like the 1N34A became available at low prices for hobbyists. You might save an allowance for weeks to buy one and then use it over and over in place of the galena crystal/cat's whisker that had to be tediously 'probed' to find a sensitive spot that would rectify the radio signal and yield the audio component of the AM broadcast." Diodes brought new sophistication for set builders, and today's students commonly use a small germanium diode, not unlike the one Rick first sampled in the 1950s, in their crystal radio sets.

Rick Marz, crystal radio expert and a volunteer in the Ask an Expert forums

Lifelong Passion

Even after decades in engineering, years in which technology has changed dramatically, Rick's interest in crystal radio has not waned. Following his early interest in engineering, and building off of his father's interest in radio, Rick first explored power electronics and then computer hardware. He studied electrical engineering in college and, in the way things sometimes work, his first career opportunity brought him full circle. "My first job out of school was with a company in Pennsylvania that built—what else—germanium and silicon diodes." Germanium diodes were used as video detectors in early televisions. As the TV industry grew, Rick says the company produced over a million germanium diodes a week to supply the demand. "That's a lot of diodes. Enough to keep any number of crystal set builders supplied forever! I still have a few small drawers full of them for old time's sake."

Passing It On

Though the parts no longer require a whole summer's earnings, Rick continues to enjoy both the history and the tinkering that a crystal radio set invites. He shares his knowledge, expertise, and interest with students who undertake a crystal radio exploration for a science fair, a school project, or as a weekend activity at home. "Several years ago I acquired the parts to create an elegant crystal set that really would be an office conversation piece. It is probably time to get it out of the garage and build it for my grandchildren."

Thanks to support from Motorola Solutions Foundation, the Ask an Expert forums are available, free of charge, to all students and parents needing assistance with a science or engineering project.

Interested in learning more about volunteer opportunities with Science Buddies?
Visit sciencebuddies.org/volunteer



When it comes to customizing robots, the spirit of innovation is alive and well in afterschool programs around the country. Extracurricular engineering and robotics clubs may provide a welcome outlet and important mentoring for students. From brainstorming designs to nuts and bolts building to learning how to integrate servo motors and computer programming, robotics projects capitalize on a student's love of tinkering—with the possibility of a clear reward in the end, a bot that does what you want it to do. A new trio of Science Buddies robotics engineering Projects Ideas offer students blueprints for hands-on exploration. Whether it is a student's first robot or merely the next, these projects offer independent challenge for at-home innovation or for a science and engineering design project assignment.


Engineers of all ages are often intrigued by the challenge of creating a robot that can make art. Some art bots are designed to duplicate or recreate a given image. Some draw pre-defined shapes or images. Some follow in the footprints of famous abstract expressionists. With new robotics engineering projects at Science Buddies, students can use the VEX system to design a robot that can draw. (A Project Kit is available in the Science Buddies Store.) With the Engineering Design Process and Science Buddies Project Ideas as a guide, what kind of art bot will you build?

An Art Automaton

Did you read or see The Invention of Hugo Cabret with your family? Did you marvel over and wonder about the mysterious automaton that Hugo's father, and later Hugo, work to repair? The automaton in Hugo Cabret is designed to write or draw something, and seeing what the machine does when Hugo successfully restores it and inserts the heart-shaped key is part of the intrigue of the story by Brian Selznik. Automata (more than one automaton) belong to a category of engineering in which a non-electric machine is created to perform an automated task. These machines, often made out of complicated clockworks, are a form of robotics.

LEGO® Robotics

In addition to VEX robotics systems, students can also explore robotics using LEGO® Mindstorms®. The new "X Marks the Spot: Build a Robot to Protect Your Treasures" robotics Project Idea challenges students with a Mindstorms system to build and program a robot sentry to guard and protect a designated space.

Depending on the ages of your children or students, you may find yourself at one of a myriad of points on an important parental continuum—that of encouraging and supporting the engineering spirit. From the time a student can first hold a chunky plastic block and connect it with another block, either flush or staggered, many parents nudge, challenge, and inspire their children to build, connect, modify, and, ultimately, to innovate. In many households, first experiences with building bricks evolve into experiences with increasingly smaller and more varied bricks, and the possibility broadens to encompass remote-controlled toys, circuit and electronics kits, and a host of other mechanical toy and DIY kit options. The parental quest? Nurture, feed, and inspire innovation.

Engineering Steps

When an elementary school student watches a mechanical bot crawl across the table and notices that if she presses and holds both of the micro-controller buttons at once, the insect will crawl in a circle rather than in straight lines, what happens next? Maybe she experiments with each button separately. Maybe she evaluates the difference in the bot's speed based on how she uses the buttons. Maybe she sees the circular shape of the bot's movement and realizes it could potentially draw a circle.

The insect doesn't really have anything to do with drawing or markers. It's just a tiny bug version of a classic remote-controlled toy car. It is an upgrade over last year's bug, however. That one just had an on and off switch. Once on, it moved without stopping. This model has given her control over the movement. In testing that control, she's made a hypothetical leap. When the student sees the circle and makes a connection to something else that can be done by combining the bug's motions and another implement (a marker), there is magic. Testing her idea by wedging a marker through the bug's appendages and setting it loose on top of a piece of paper may, in fact, generate a circle. If it takes several tries to find the right angle at which to position the marker, or just how far you need to stick it through the bug's legs, that's part of the process. Similarly, pens and markers of different weights may work differently&mddash;or may not work at all. The bug is small and lightweight. That has an impact on what kind of marking instrument the bug can drag along in its circuitous path. But, finally, there is a circle. A circle that a small bug robot has drawn.

In this case, the ability to control the drawing process is limited. But for many parents and teachers, the simple "aha" moment, and the satisfaction of seeing the circle on the page, is an important part of science, technology, engineering, and math (STEM) education. To feed this kind of excitement about engineering, robotics clubs and groups are springing up in an increasing number of schools and after-school programs, often with the support of companies like Motorola Solutions Foundation. Many of these groups work with VEX robotics kits. Part screw-it-together, part brainstorm and modify, part hacker DIY, part programming, and part collaboration with peers and clusters of parents, teachers, and role models, VEX systems can be a fulcrum for middle and high school robotics exploration.

For the Game of It

This year, student robotics teams planning to participate in VEX competitions are preparing for the VEX Sack Attack. To succeed in the Sack Attack challenge, teams will have to design and build a bot that can quickly and efficiently scoop up "sacks" and deposit them in a scoring area to earn more points for the team than the bot on the other side of the 12' x 12' arena within a set amount of time. Different colored sacks earn different points, and there are multiple types of goals, each worth different point values. In preparation for an official bot versus bot Sack Attack showdown, robotics team members often meet in the afternoons and on weekends. Many teams, especially at the middle school level, first assemble a baseline or "kit" sack attack bot. The "kit" bot is functional, but as groups test and observe their bots abilities, they are encouraged to think about ways to enhance the bot's ability to quickly and efficiently perform its task. Following steps of the Engineering Design Process, students collaborate customizing their robot and prototyping and testing new features, behaviors, and programming. What modifications might make the bot easier to maneuver or better able to pick up and deposit sacks? What custom behaviors might give their bot an edge?

Building Bots

Using core VEX components and extrapolating from robotics club investigations, students can independently design and test custom bots built to perform a range of different tasks. An exciting new trio of Science Buddies Project Ideas challenges students to use a VEX kit to create a marker-wielding robot, one that can draw a picture. The tiered suite of projects begins with "Robot Picasso: Building a Robot That Creates Art." In this robotics Project Idea, students are guided in thinking through ways to turn the Vex claw bot into a picture-drawing robot. While basic guidelines for assembly are given, students will need to innovate and troubleshoot their own drawings and designs to construct their drawing bot. At the same time, students will face the limitations of their bot as they test to determine what it can and can't successfully draw—and why.

With the basic "Robot Picasso" drawing bot on hand, a young engineer can tackle more sophisticated challenges to give the bot more refinement and the ability to use more than one color or other tools. The "Motorized Michelangelo: Building an Art Robot with Servo Motors *" Abbreviated Project Idea encourages students to incorporate a servo motor in the robot, allowing greater control. This robot, for example, can be programmed to lift the marker at a certain point rather than drawing a continuous and never-ending line. The "Drawing Dalibot: Designing an Art Robot That Switches Colors *" Abbreviated Project Idea challenges the student to extend the exploration and enable the bot to use more than one color. Controlling how multiple colors are used, selected, and changed offers a fun and sophisticated robotics engineering project that requires the use of servo motors and programming using RobotC.

These three Project Ideas are just the beginning. We encourage students to adapt the core project concepts to further refine the art bot or to create an entirely new kind of robot that builds upon behaviors and functionality from the art bot! Before your students disassemble and start something new, send Science Buddies a picture. We would love to see what your students imagine, innovate, and build!

Science Buddies Project Ideas in robotics are sponsored, in part, by Symantec Corporation and the Northrop Grumman Foundation.



Americans spend billions on cosmetics every year. Who creates and tests all of these shampoos and lotions? Cosmetic chemists!

By Kim Mullin

Emma Sesar was surrounded by science fair attendees last Spring as she handed out samples of the lip balms she developed as part of her science project.
Why was Emma Sesar surrounded by groups of young girls at her school science fair? Lip balm samples! For her sixth-grade science project, Emma chose the "Lotions and Potions: Lessons in Cosmetic Chemistry" Project Idea because she is a fan of lip balm and wanted to explore the world of cosmetic chemistry.

Guided by recipes and procedures in the Project Idea, Emma created three different lip balms and then formulated questions to ask her test subjects. As she cooked up her custom creations, she had fun learning about the different components of lip balms, such as emollients, emulsifiers, and stabilizers, especially because many of the ingredients smell so good. Throughout the process, Emma found the Science Buddies Project Guide "extremely helpful" and was pleased that her project turned out so well.

What really surprised Emma, however, were the crowds that swarmed her at the science fair. After working hard on a project, the science fair allows students to show off their work, and Emma was certainly able to do that! Her creative project display board and enticing lip balm samples attracted a lot of attention. "I was surrounded by young girls for the entire fair," says Emma. "I ended up giving some students second, third, and fourth testers!"

A Positive Science Experience

Will Emma be the next Estée Lauder? She has many different interests, so she doesn't know what she wants to do when she grows up. However, she looks forward to perfecting her lip balm recipe and also plans to participate in next year's school science fair!

Read about Emma's teacher's use of Science Buddies in the classroom and other student science successes in the Science Buddies in Action area.

New Project Kit!

Project Kit
A Science Buddies Project Kit is now available for the "Lotions and Potions" science project. Project Kits make it easy to gather the materials, including specialty or difficult-to-find items, needed for a Science Buddies Project Idea, and kit supplies arrive in one convenient box. View a full description of the "Lotions and Potions" kit contents.


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