Scratch, Electricity & Electronics Science Projects (Page 9)

Smart Medicine Cabinet: Build a Sensor That Reminds Patients When to Take Medication

Science Fair Project Idea

Scientific Method

Have you ever had to take prescription medicine to get over an illness? To get better, it is important to take the medication in the proper manner and at the proper time. Wouldn't it be cool if there were a tool or piece of automated equipment that held your medicine and reminded you to take it? A tool that would know when you picked up the bottle and took your medicine? Building a smart medicine cabinet is what this science project is all about! Read more

Simple Circuit Logic with Switches: An Electric Puzzle

Science Fair Project Idea

Scientific Method

Here's a puzzle you may have heard before which you can build as a simple electric circuit. First, the puzzle: a farmer is traveling to market with his cat, a chicken and some corn. He has to cross a river, and the only way to cross is in a small boat which can hold the farmer and just one of the three items he has with him. The problem is, he has to be very careful about what he chooses to leave behind at any time. If the cat and chicken are left alone, the cat will eat the chicken. If… Read more

Using a Magnet as an Electrical Current Detector

Science Fair Project Idea

Scientific Method

An electric current produces a magnetic field. You can take advantage of this fact to make a simple apparatus to test the electrical conductivity of various materials, including both solids and liquids. The detector consists of a coil of wire, with a magnetic compass inside it. You connect one end of the coil to a D-cell battery. The other end of the coil is connected to whatever material you are testing, and the material, in turn, is connected to the other end of the D-cell. In other… Read more

Two-Point and Four-Point Methods for Measuring Small Resistances

Science Fair Project Idea

Scientific Method

Measuring the value of a resistor with a multimeter is pretty simple. You set the multimeter to measure resistance, connect the two leads to the resistor (possibly using some handy alligator clips), and read the resistance value. This is called a two-point measurement (one probe on each of the two resistor leads). But what if the resistance you want to measure is very small, in the milli or micro-ohm (mΩ or μΩ) range? This can introduce problems because many low-cost multimeters… Read more

Effect of Different Materials on a Magnetic Field

Science Fair Project Idea

Scientific Method

You've seen that a magnet's attractive force can cause a small object (like a paper clip) to "jump" to the magnet. So a magnetic field can act through the air, but what about other materials? Here's an experiment you can do to find out. You'll need a strong bar magnet, a stack of books, a paper clip, some thread and tape. Place the bar magnet underneath the top book in your stack, so that it sticks out. Tie a piece of thread (as long as the stack of books is high) to a paper clip. You… Read more

Linear vs. Logarithmic Changes: What Works Best for Human Senses?

Science Fair Project Idea

Scientific Method

If you want to get your friend's attention at a crowded sporting event with lots of people cheering, you need to shout. If you're trying to do the same thing in a quiet library, a whisper works. The detection limit for each of our senses depends on the amount of "background" stimulation that is already present. This project uses an LED control circuit to investigate detection of changes in light levels. Read more

Design a Wearable Air Quality Index Monitor

Science Fair Project Idea

Engineering Design Process

You can look up information about local air pollution, such as the Air Quality Index (AQI), online or even get alerts on your phone. But what if you could wear a device that continuously monitors the air quality around you in real time, alerting you to unsafe levels? Such a device could alert a person with asthma when they need to go inside, let you know if smoke from a nearby wildfire is drifting in your direction, or signal when it is time to take a break on a hazy summer day. The Science… Read more

Upstairs, Downstairs: Turning on a Light from Two Places

Science Fair Project Idea

Scientific Method

Maybe somewhere in your home there's a long hallway or a stairway with a light that you can turn on from either end. It's a nice convenience, but did you ever wonder how it's wired up to work that way? The goal of this project is to build a similar circuit with switches, flashlight batteries and a flashlight bulb (obviously, household circuits are not safe to experiment with). You'll need to understand the difference between connections made in series and connections made in parallel in an… Read more

Design Clothing with Built-In Sensors

Science Fair Project Idea

Engineering Design Process

Have you ever worn a costume that lit up or played sound? Have you ever wished you had a suit of armor with built-in moving parts like a superhero? What if you could make your costume or suit react to your own movements or even other people who bump into you? The Science Buddies activity Weaving a Wearable Touch Sensor shows you how to make a capacitive sensor that responds to touch and can be woven directly into fabric (Figure 1). Can you design a piece of clothing that includes one… Read more

How Far Can Sparks Jump?

Science Fair Project Idea

Scientific Method

Piezoelectric barbecue fire starters work by creating a spark that ignites the volatile lighter fluid, which then starts the charcoal burning. They are low current, high voltage devices. How high does the voltage have to get to make a spark in air? This project shows you a way to find out by with an inexpensive experimental setup to measure the distance that the spark can travel between two spherical electrodes. Read more

Scratch, Electricity & Electronics Science Projects (95 results)

Explore Our Science Videos