Science Fair Idea - I can't choose!

[deleted-42343]

I just realized I didn't completely answer one of your questions. For my high school projects, in 10th grade I got my idea from a science article I read about "mashing" solid chemicals together and getting them to react with no solvent. I repeated their experiment (though slightly modified it) and that's where I found out that original research is highly valued in high school (and my project was not original). My next project spanned two years and I got the idea from my 10th grade project. I pursued an accident that occurred when I was looking at some digital images. I ended up doing something original that was very satisfying and fun to work on. Just goes to show you that accidents can be a good thing.

If you haven't yet, check out this roundtable article about finding an advanced project idea: https://www.sciencebuddies.org/science- ... 2008.shtml

In that roundtable, I think Terik and I are saying the same thing, but he was interpreting "original" as something that had never been done before. In my mind originality can be improving something or doing something completely new (though "completely new" is pretty difficult to achieve, as everything is based on some sort of foundation).

[donnahardy2]

Hi Irregular,

Thanks to Amber for the extremely interesting history of her science fair projects, and for putting things into perspective. Hopefully Amber’s story will help you develop a long range plan for your future. I completely agree with Amber that understanding the chemistry and the science behind a project is critical to success.

Looking at the 3 finalists on you science fair project list, I still think any would make a good project. Here are some comments that may help you decide.

1. The MFC project includes recycling, microbiology, and electrochemistry so has a variety of scientific concepts for you to learn. This is also the most difficult and time-consuming project. You will be working with mud in this project, so if you don’t like the idea of working with mud, you should not do this one.

To answer your question about safety issues with the MFC project, you should know that almost all mud bacteria are not human pathogens. However, since you are working with a mixed culture of unknown organisms, you would want to take the basic precaution of wearing gloves and you should read through the safety information provided in the science buddies guide. There are a few anaerobic bacteria that cause food poisoning and infections , http://www.merck.com/mmpe/sec14/ch178/ch178a.html, that are normal flora in the soil, so you would not want to get any mud in food you are going to consume or in an open cut. However, if you take basic precautions, there should no problem with doing this project. One of my hobbies is gardening, so I work with mud all the time and I highly recommend it.

2. The solar panel project is a nice, clean project that requires understanding basic electricity and it won’t take too long to do. I have noticed that sometimes very basic projects that are very well done are the best ones at the science fair, so I would recommend this one if you don’t pick the MFC project.

3. The oxygen project requires ordering an oxygen test kit, so before you pick this project, call the supplier and find out if a kit can be shipped in time. You can’t do this one if you don’t have the test kit. If you do this project, you will have to find out what’s in the test kit and how it works so you can explain the chemistry on your project board. This project could be interesting, depending on the samples you select to test.

When thinking about each of these projects, try to think of the question you will ask that will lead to your experiment. That should help you focus and limit the scope of your project.

Let us know what you decide to do.

Donna Hardy

[irregular]

Wow, thanks so much, Donna and Amber!

Amber: Thanks for making me realize that I can start out small and know my stuff, and in high school pursue more advanced and original projects. I installed chime, and must say is very useful! I'll try to explore any textbooks or science books around the house...

Yes, science magazines/articles, I've found as well, are very inspiring! Additionally, it's very refreshing to know that with a simple experiment and knowing your stuff, you can be passionate and do well! I think I didn't realize that asking and understanding "WHY?" is as important as aiming for originality.

Lastly,thanks for telling me about the Young Scientist Challenge! I really appreciate everything!

Donna: Yes, indeed, Amber helped me with understanding my plan and key things for a middle school project.

Hmm.. I think I narrowed my projects down to two, eliminating the oxygen experiment. I will present my two projects to my parents, receive their opinion, and continue background research. As I mentioned yesterday, I will confirm the project by Friday.

I think that I'm willing to give myself a challenge with the Microbial Fuel Cell project. A lot of people at my fair, even one in the junior level, develop original projects. Even though the MFC project may have been done once or twice at my fair, I'm confident that with adding a little twist on the project and knowing my stuff, I can be successful. The MFC project is definitely winning right now. Plus, have free time these days since many of my projects are complete. I will be as safe and careful with the project, for sure. Thanks for the explanation

If for some reason my parents point out a major obstacle with the MFC project, I will pursue the Solar Cell project. I am a little less passionate on the solar cell project as I was enthusiastic about exploring alternate methods of being environmentally friendly.

I will brainstorm my final experiment question and present it to you in my next response.

Thanks for your time and help.

[donnahardy2]

Hi Irregular,

I think you are making progress now! Once you decide which project to do, you will be more in control because you will have a definite goal and not the uncertainty of not knowing what you are going to do. Presenting the project to your parents is a really good idea as they can help you focus on developing the specific experiment.

Do let us know what you decide. I can help by explaining the chemistry behind your project.

Donna Hardy

[irregular]

Hello!

Yay, it feels great to have more control, certainty and clarity in my goal! So far, I showed my mother. My dad is quite busy these days with extra work, so I'll show him as soon as possible (that will probably be tomorrow). Since he is an engineer, I will probably have access to some equipment like a multimeter (I had access to a conductivity meter last year).

In short, the project is about creating a Microbial Fuel Cell to create clean, renewable energy as well as 'leaving behind clean drinking water'. This project tests various mud samples to see which is most efficient. As I mentioned before, I would like to make this project slightly more original, for me. When I choose a variation, it will ask a different question. Three possibilities for originality include:

1) Making the MFC out of cheap/unusual materials - How can I cheaply and efficiently produce energy using a renewable resource?
2) Controlling the temperature (as you suggested) of the MFC - How can I produce energy quickly using a renewable resource? (This variation means that I control the two bacteria samples at 2-3 temperatures.)
3) Using cheap materials to make the MFC. Then, control the temperature of the MFC - How can I cheaply and efficiently produce energy using a renewable resource? (This variation means that I construct a cheap MFC. Then I control two bacteria at 2-3 temperatures. Or would that become too complicated?)

Do you think those questions seem fine? Can I word the questions more effectively/differently?

Just a last thought - this project involves comparing two mud samples. Could I research WHY I get the specific data I obtain at the end? What I mean is that if Fuel Cell 2 produces more electricity than Fuel Cell 1, could I analyze the different components of the mud and see what Fuel Cell 2 had that made it more efficient?

Thanks so, so much! *fingers crossed that I'll be able to do this experiment!*

[MelissaB]

Hi,

I think most experts will steer you in the direction of having fewer independent variables rather than more. However, if you have time, supplies, etc., it would be entirely possible to do an experiment where you change three variables (mud sample, expense of materials and temperature). I'm assuming that in addition to building a 'cheap' one, you would also build one at a 'normal' expense and then compare their output? You could certainly do this and then compare the output of both with each mud sample at two or three different temperatures...if you have the time, of course. It might be better to focus on one of the three ideas first, so you can be sure that you'll get at least some data.

As for trying to find out why one produces more or less electricity, I'll let a microbiologist answer that; I'm sure it's possible, but I don't know how doable it is for a middle-school student

[irregular]

Hi!

Thank you so much, Melissa! Yes, indeed it will take more time and more materials to have more independent variables. I think making two MFCs will take more time and money, so I will focus on one MFC, using available and less-costly materials. To make the MFC, my main resources are:
http://sciencebuddies.com/science-fair- ... x&from=TSW
and
http://www.engr.psu.edu/ce/enve/logan/b ... e_cell.htm

So, I think I will focus on collecting two-three mud samples and experimenting with two-three temperatures, of course if time permits. As for the question of different bacteria, I will be looking forward to the explanation of a microbiologist. I understand how I may not be able to complete that since it may be complicated, though I'm a little curious of the method how you could determine that.

Thanks again!

[donnahardy2]

Hi Irregular,

Melissa is right; you definitely don't want to plan to do one more thans one variable at a time. I normally recommend doing one experiment, repeating it, and then, if you have time you can do another experiment. This will give you a really good project. So you can compare different designs, different temperatures, or different sources of mud, but just work on one independent variable at a time.

You need to do more background research for now and perhaps the question for the final experiment can be developed based on your reading. In the meantime, you can start gathering materials and identify a location where you can collect mud that has been protected from oxygen (anaerobic). There are lots of materials that need to be collected for this project and you will need to drill holes in the containers you select.

When is your project due? You can make a time line and make sure you will have time to complete at least one set of experiments one week before the project is due, leaving one week to write up your board.

Here are some questions you should try to answer:
1. What quantity of electricity can be produced by a typical microbial fuel cell?
2. Which bacteria produce the most electricity?
3. How long does a MFC last? (the science buddies project says the mud has to be used with a day)
4. What is the optimum temperature? (has anyone done this before?)
5. What types of materials have been used to make MFC's (is there anything that hasn't been used)
6. How to bacteria product electricity?
7. What is electricity?
8. How is electricity measured?

I had promised to explain the chemistry behind your project and so I’ll start with bacterial respiration.

Here is a website that describes aerobic (with oxygen) respiration. Respiration is the breakdown of organic molecules like sugar to produce energy and the chemical reactions leave the organism with extra electrons that must be transferred. If there's no electron acceptor available, respiration will not occur. Aerobic bacteria use oxygen to accept electrons that are needed to produce energy. This is similar to humans; we use oxygen (to burn glucose and produce energy) and the extra electrons are transferred to the oxygen atom.

http://en.wikipedia.org/wiki/Aerobic_organism

Anaerobic bacteria are those that grow without oxygen and use other molecules to accept electrons produced from respiration. You have not had chemistry yet, but try reading the following website and understand as much as you can. Let me know if you have questions. This is an important topic for your project.


http://dwb.unl.edu/Teacher/NSF/C11/C11L ... Anaer.html

Here is some information about anaerobic bacteria. These are organisms that grow without oxygen, and may even be harmed by the presence of oxygen. When you collect the anaerobic mud sample, you will need to be careful to avoid exposing the sample to oxygen so you don’t kill of some of your subjects.

http://en.wikipedia.org/wiki/Anaerobic_organism

You will be collecting benthic (bottom of the stream or lake) bacteria for your sample. Here is an abstract that studies the growth and nutritional requirements of one particular benthic organism.

http://www.springerlink.com/content/u56238n1t2t14403/

Here is an article on obligately anaerobic green sulfur bacteria, which are found in the bottoms of lakes. Look at this article and see if you can find information about growing these bacteria. Since the production of electricity in the microbial fuel cell depends on the growth of the bacteria, knowing about the culture of the organisms might be helpful for your project.

http://mic.sgmjournals.org/cgi/reprint/144/4/1051.pdf

This is getting very interesting. Can you see the value of doing the background research? Are you getting any ideas that might help you design the final experiment?


Donna Hardy

[irregular]

Hello Donna!

I completely understand how both Melissa and yourself want me to do one variable at a time. Due to time constraints, I will test two-three mud samples at two-three temperatures. Since designing another MFC will consume time, I will release that variable idea this year.

I have started my background research - yesterday I searched some keywords and questions (suggested by the Science Buddies Project) into Google and saved the collection of links. Today, I proceeded on reading the Background Research portion of the Science Buddies Project Guide. By tomorrow/day after, I am planning on gathering all background research information. I will then read and study my Background Research (2-3 hours on weekdays, 3+ hours on Saturday and Sunday). Additionally, over the next week I will collect materials and equipment needed for the experiment. Finding anaerobic mud shouldn't be too much of a hassle as my city has plenty of various water sources. Thanks for the research questions!

My project is due on the second of April, but I would like to be done at least one week before. Here is my timeline:

January 29 - February 7 - Gather, read, study and understand background research. Collect all materials, identify anaerobic water source.
February 8- February 14 - Write research paper.
Febrary 15 - February 19 - Construct Hypothesis, plan out experiment. Start assembling experiment.
February 20 - February 28 - Carry out experiment, once per weekend (a total of two weekends included in that time)
March 1 - March 7 - Analyzing Data, Drawing Conclusions, purchasing Display Board
March 8 - March 21 - Write final report. Practice possible questions and communicate.

What do you think of my timeline? Are all the time lengths appropriate?

Wow, thank you so much for the clear explanation and wonderful links! I will check them out for sure! I have gathered a few other links to the subject of respiration as well.

I am definitely understand the importance or background research now! Once I finally obtain all my background research, I will proceed to learning and understanding. Or do you suggest that I read as I collect the information?

Thank you so much for your efforts, time and patience!

[donnahardy2]

Hi Irregular,

Your timetable looks good, and you have a little extra time to spare in case you are delayed in any of the steps. This is wonderful that you have until April 2; you should be able to do a really good job on this project. You will find that it is very worthwhile to spend a whole week on your background reading:

Here are some additional links for you:

You probably found this one on your own, but it is a really good review of the topic. One interesting fact is that most microbial fuel cells are inactive because the bacteria can’t transfer electrons directly to the medium. A mediator is required to allow electron transfer. This means that your MFC won’t generate any electricity on its own unless your sample contains bacteria that are electrically active. Since you won’t know in advance if your mud sample contains electrically active microbes, you should plan to include a mediator. This site also includes a good description of how the electrons are generated from metabolizing sugar and how the flow of electrons creates electricity.

http://en.wikipedia.org/wiki/Microbial_fuel_cell

Here is a site that reports an improved design for an MFC. A cloth is placed between the anode and cathode chambers to reduce the resistance of the flow of electrons and this resulted in a 10x increase in the production of electricity.

http://www.sciencedaily.com/releases/20 ... 155306.htm

Here are some pictures of various designs:

http://images.google.com/images?hl=en&q ... afe=active

Here’s a practical application for a MFC:

http://www.treehugger.com/files/2008/09 ... lagers.php

Next is an excellent reference for your project. This is a review article from a scientific journal. Review articles don’t report results of an experiment, but they summarize the current scientific literature on the topic. It gives you an idea of everything going on in the field. This article should help you decide how to report the results of your science project and includes the proper terminology for the topic. It will also help you know what research has been done on MFC's and maybe give you an idea of what else needs to be done.

http://pubs.acs.org/doi/pdf/10.1021/es0605016

Next is another scientific paper that gives information on using MFC’s for wastewater treatment. This is a little complicated, but do try to read and understand as much as you can.

http://pubs.acs.org/doi/pdfplus/10.1021/es062580r

This is another review article that includes variations in design and challenges in making an MFC.

http://ejournal.vudat.msu.edu/index.php ... le/232/256

You should consider printing the good references you find and filing them in a 3-ring binder. This way they will be handy to refer to when you need them. These references will be the bibliography section of your project.

Also, make sure you have a lab notebook on your list of items to purchase. You will need a bound notebook to record the building of the MFC and the results of the experiments.

Questions to think about while you are reading:

1. Can I think of a better design for MFC’s?
2. Can I think of another application for MFC’s?
3. What will I use for a mediator? Or where can I find electrically active bacteria?


Let me know if you can’t open all of the links; I’ll upload the references for you if necessary. Let me know if you have any questions about the information in any of the references.

Donna Hardy

[donnahardy2]

Hi again,

Here is the science buddies website primer for electronics. This is the basic information you need to understand for your project, and there is a useful link explaining how to use a multimeter.

https://www.sciencebuddies.org/science- ... ntro.shtml

Donna Hardy

[irregular]

Hello Donna!

Yes, I'm pretty satisfied with my plan and hopefully I will be on track!

Thanks for the informational websites! Yes, you were right, I did find the first link already, but thanks for the information about mediators! Additionally, thanks for the other great links!

Okay, so I think I have between 40-50 links to help my background research. Do you think that's a good amount of references? I have a few links for each research term, concept, etc. Personally I think that I have a good amount of references to work with, so I'll proceed to start reading and understanding the references. If I have any questions, thankfully you're there to help me along the way!!! Also, I'll dig any science books or textbooks I find at home. It's great because my family has a set of DVD lectures on science which touches on the chemistry and biology relating to my project!

So when I start reading my background research I'll keep track of the best links and print them off. I remembered that I'll need a lab notebook last night, and so I read the Science Buddies articles on Lab Notebooks. I also found a notebook at home for usage. So far, I included my timeline in there, a few questions I have for my experiment and materials, and things to touch on during background research.

Thanks for all your help!

EDIT:

Hi Donna! I was reading through some background material, and came across three webpages:
1. http://www.microbialfuelcell.org/www/in ... trate.html
2. http://www.microbialfuelcell.org/www/in ... nisms.html
3. http://www.microbialfuelcell.org/www/in ... -MFCs.html

I was just wondering if these references are relevant and of use to my experiment. If yes, could you help summarize/help me understand what they are describing?

Are these three Scientific American articles useful?
1) http://www.scientificamerican.com/artic ... t-wastewat
2) http://www.scientificamerican.com/artic ... rts-biomas
3) http://www.scientificamerican.com/artic ... ry-convert

Additional questions:
1) Most of my references describe that the MFC uses 'organic material/compounds' - that would be my mud, right? If I wanted, could I substitute that mud for wastewater? If I used wastewater, I would produce the electricity and have clean drinking water, right?
2) Some say that proteins or glucose is used as well (http://www.springerlink.com/content/h680w58354168325/). How is this possible?
3) What happens to the bacteria after it releases the electrons? Does it die? What do I do when the electricity has been produced?
4) How would I safely dispose my MFC after finishing my experiment? Is it dangerous to dispose because of the bacteria?

I am not able to open:
1) http://pubs.acs.org/doi/abs/10.1021/es0 ... ode=esthag
2) http://pubs.acs.org/doi/abs/10.1021/es0 ... ode=esthag
The website is wanting me to pay to view the journals. I guess I would have to do without them unless I pay, right?

[donnahardy2]

Hi Irregular,

I think 40-50 references should be good to give you a good background on all of the topics related to this experiment. You will have to develop a good understanding of microbial respiration and electrical circuits, and you need to be familiar with all of the research that has been done so far on microbial fuel cells, so there’s a lot of territory to cover. You are very wise to realize that you need to spend time reading and asking questions to make sure you understand the scientific concepts.

I read through the science buddies project guide again last night, and I realized why this project is rated a 10 in difficulty. The actual construction of the MFC is very complicated and so I think you should start the actual construction of the unit as soon as you can gather the materials. It’s going to take a lot of time to put the unit together before you can actual do an experiment.

You are proficient in finding good links for your project. Here are some comments:

1. http://www.microbialfuelcell.org/www/in ... trate.html

I like this reference because it’s a summary of several research papers and it includes the actual references so you can look up the details in the materials and methods sections. It also answers a concern I have had about using just a random sample of mud for the project. The production of electricity in an MFC depends on the rate of microbial metabolism. If the sample of mud doesn’t have any nutrients (electron donors) left in it, the microbes are not going to be growing and metabolizing and won’t produce much power. According to this source, MFC researchers have tried a number of different food sources (electron donors) and have found that adding acetate to the anaerobic chamber increases power output better than other sources. For your project, you could consider looking for a local industrial wastewater (acid mine, brewery, paper recycling, (something safe enough to work with), that contains a reduced molecule that could be used as an energy source. Developing this idea could make your project very unique.

2. http://www.microbialfuelcell.org/www/in ... nisms.html

This is an excellent reference also; it explains how and why bacteria transfer electrons during respiration. The chemistry here is the basis of the MFC. The significance for your project is that an MFC won’t work without a terminal electron acceptor, and you need to make sure your system has a suitable molecule available in your system. Read this reference until you understand it, and use the information in the background section of your project board.

3. http://www.microbialfuelcell.org/www/in ... nisms.html

This is another very good reference because it summarizes many of the factors (short circuit, high resistance) that will affect the power output on your MFC. Save this reference for troubleshooting in case your MFC doesn’t work the first time, or if it stops working after a while.

4. http://www.scientificamerican.com/artic ... t-wastewat

This is not really a reference, but it includes general information about the species of bacteria that are best as generating power. You will be using a mixed culture of bacteria and identifying them is outside of the scope of your experiment, but possible a good topic for a future project.

5. http://www.scientificamerican.com/artic ... rts-biomas

Like #4, this is more of a news report rather than a reference, but it does refer to a scientific paper published in Environmental Science and Technology that might be interesting. The topic, which is the use of a microbial fuel cell design to generate hydrogen gas as a source of energy, is interesting but not really related to your project.

6. http://www.scientificamerican.com/artic ... ry-convert

This is interesting. It’s a report of a specific bacterium, Rhodoferax ferrireducens that is able to transfer electrons directly to the electrode of an MFC without a mediator. This could be related to your topic if you were to obtain this organism and use it in your MFC. This reference could also have other significant implications for your project.

Here is the original reference reporting the isolation and identification of this interesting organism.

http://ijs.sgmjournals.org/cgi/reprint/53/3/669

This organism was isolated from fresh water in Oyster Bay, VA and it can use lactate and acetate as an electron donor (energy source) and uses Fe(III) as an electron acceptor. You could incorporate lactate as electron acceptor into your experimental protocol if you want to. Also, this paper has some information related to your current experimental idea (comparison of temperatures). This bacterium is a psychotroph (cold loving) and its optimum temperature for growth is 25 degrees Centigrade.

Answers to additional questions:

1. The organic materials described in the MFC references refer to the molecules that are donating the electrons to the circuit. This is the glucose, sucrose, acetate, rotting vegetables, proteins or whatever the electron (food, energy) source is.
2. There are bacteria that will use any carbon source as a source of energy (electrons for the MFC). Humans can also use glucose and proteins for an electron/energy source, but we use oxygen as the electron acceptor.
3. The production of electrons is due to the respiration (breathing or burning food for energy in humans). The MFC just “steals” some of the electrons produced to create a complete circuit. The bacteria should keep growing and producing electrons.
4. Since the MFC will contain a high concentration of unknown microorganisms, you can put the contents in a bucket and add bleach (strong oxidizing agent) to kill the organisms at the end of the experiment.

I will upload the journal articles for you. The organization I work for pays for a subscription for these articles, and we have permission to share them. You don’t have to pay for anything. Using scientific references is essential for a prize-winning science project because prior publications lay the foundation for the next experiment

Donna Hardy.

[irregular]

Hi Donna!

Yes, indeed, there's a lot to cover!From the parts of the MFC, to bacteria, to the electrons.. As for the construction, I understand that a lot of time and care will be needed. However, I think I will need to do a lot of shopping if I construct the MFC showed on the Science Buddies website. Hence, I found a few other resources which explain to me how to make an MFC, with cheaper materials. I think that if I substitute a few material it will take me less time and it will be proof that it is possible to economically and ecologically produce an MFC.

1) http://www.instructables.com/id/Simple- ... -An-Algae/
2) http://www.microbialfuelcell.org/MFC/tutorials.htm
3) http://www.engr.psu.edu/ce/enve/logan/b ... _guide.htm

Thanks a lot for the helpful comments! Right now I'm not too sure on a few terms so I'll read more background research references. Once I understand the terms better, I will refer back to these references/articles and your comments.

Additionally, thanks for the clear answers. They really give me a better understanding!

Lastly, I really appreciate that you will be able to upload these articles for me. It will help me in constructing my MFC, understanding my MFC and thinking creatively.

You are a big part of my experiment are permitting me to take on such an interesting and complex experiment by helping my understand and giving me amazing and intelligent tips. I am so greatful!

[donnahardy2]

Hi Irregular,

Thanks for including the links to the alternative MFC construction directions. I agree that using less expensive materials is a good and idea, and presumably this plan will work well since it is based on a plan suggested by Bruce Logan from University of Pennsylvania, who is also the primary author of the review article I am sending. However, the construction of an MFC involves 9 major steps and involves a glue gun and soldering. The finished product must have a complete circuit and it can't leak. Have you ever soldered anything before?

The review article will be uploaded in 5 parts; I can only send 2-3 pages at a time. This article was published in 2006, and it covered different materials and methods used to construct MFC’s and suggests ways to analyze the performance. You can read this article and then look for newer references that have been published since 2006 to have a complete history.

Donna Hardy

MFC Logan review 1.pdf

(191.27 KiB) Downloaded 330 times

[donnahardy2]

Here's part 2.

lMFC Logan reivew 2.pdf

(98.88 KiB) Downloaded 347 times

[donnahardy2]

Part III

MFC Logan review 3.pdf

(211.26 KiB) Downloaded 330 times

[donnahardy2]

Part IV

MFC Logan review 4.pdf

(226.79 KiB) Downloaded 394 times

[donnahardy2]

Part V.

MFC Logan review 5.pdf

(209.65 KiB) Downloaded 308 times

[irregular]

Hello Donna!

Yeah, thanks for looking over those additional MFC construction directions. Unfortunately I have never soldered anything before and do not have a glue gun. I will compare the different methods and talk to my dad about his opinion.

Wow - I'm speechless! This paper is looking very helpful and by the way you state it's purpose, I think it'll be wonderful! I will definitely look for newer papers as well. Thanks so much for your kindness!

Okay, so my goal by the end of today is to completely understand the MFC itself - anode, cathode, circuit, salt bridge. It's kind of confusing because when some references explain the MFC and describe the process, they mention some terms I'm not familiar with and haven't read on yet. I also want to finalize the materials I will be using and which MFC design I will use.

Just one question: I looked over the HowStuffWorks article on Fuel Cells (http://auto.howstuffworks.com/fuel-effi ... /printable) and I am surprised that they never mention the word 'bacteria' once! I realized that this article is specifying to cars, but then I looked over this article (http://science.howstuffworks.com/body-g ... /printable) and it specifically mentions the MFC and bacteria. So why do they never mention bacteria in the Fuel Cell article? They mention the anode/cathode/PEM design and everything else...

Thanks so, so, so much!

[donnahardy2]

Hi Irregular,

You do ask good questions. A fuel cell is a unit that generates electricity. Only a microbial fuel cell uses living bacteria to generate the electrons. Read the first page of the review article carefully because it does a good job of defining what a microbial fuel cell is; it is a sustainable production of electron production at the anode electrode and consumption at the cathode. All other types of fuel cells are not microbial fuel cells. One of the stated purposes of the review article was to define standard terminology, so do look at the article carefully and use the terms the same way the author does.

What type of engineering does your father do? Do you have someone available who can show you how to drill, solder, and construct an electrical device? It is very helpful to have someone show you how the first time you learn a new technique. Doing water-tight gluing and soldering wires are techniques that improve with experience.

Donna Hardy

[irregular]

Hello Donna!

My, that makes things a whole lot easier to understand. Okay, so I've got that cleared. Since there are so many references out there, I think that sometime during or at the end of this week, whenever possible, I will write up a piece describing the MFC which I can use in my Research Paper. This 'piece' will explain the MFC itself - the parts of the MFC, as well as how the MFC works.

As for the scientific paper, I am eager to start reading it. With school and everything, I'm going to print it off so I can read it whenever possible and refer to it. It sounds amazingly helpful.

My father is a mechanical engineer by profession, and he works for a company which produces rubber. So his company is mostly chemistry-based. He will be able to do the drilling, but I will ask him about soldering. Honestly, I'm not sure whether he knows how to do it or does it at his plant. I will get back to you on that ASAP.

Lastly, I am thinking of a possible place where I can conduct my experiment. I don't want to risk doing it in the kitchen/house, so I'm thinking perhaps my garage? What do you recommend?

Thank you very much for you help, Donna

EDIT: In case my father or anyone I know doesn't have any soldering experience, I have a video I can use to guide me: http://blog.makezine.com/archive/2007/0 ... ake_v.html. (It's the MP4 link)

Also, I found two scientific papers via Wikipedia's article on MFC's.
1) http://www.pnas.org/content/104/47/18871.full.pdf+html
2) http://www.nature.com/ismej/journal/v1/ ... 20074a.pdf

I have briefly skimmed through them, and find them interesting. As to my understanding, the first one is based more on hydrogen, though the MFC is important. What do you think?

Lastly, I was reading the MFC article from Wikipedia (http://en.wikipedia.org/wiki/Microbial_fuel_cell) and scrolled down to the "See Also" section. There are links to other Wikipedia articles with terms I haven't studied at all. About all of them relate to hydrogen - why is that? Do you recommend I study those terms?

[donnahardy2]

Hi Irregular,

Are there any electrical engineers at your father’s company? I think I will see if we can find a science buddy expert on electrochemistry to help on this project.

It’s good to be thinking about the details of your experiment. You have not worked with anaerobic bacteria before, but you should know they are all aromatic and you definitely don’t want to work with them in the house. Your family would complain. What is the temperature is the garage?

I didn’t have time to look at the 19 minute video on soldering, but that’s enough time to cover this subject and get you started. I recommend doing a few practice solders before working on your device.

You are doing a great job in finding references. The first reference describes hydrogen producing microbial fuel cell and it authored by Bruce Logan, one of the authors on the MFC review article. In a hydrogen fuel cell, an external voltage is added to the electricity produced in the anode chamber, and the cathode chamber is anaerobic instead of aerobic. The second article looks like another review article and I will read it tonight.

Donna Hardy

[irregular]

Hello Donna!

Yes, I checked with my dad and he said that there are electrical engineers at his plant. He also said that he has only soldered once or twice in his childhood with a soldering expert. Thanks for the help!

When we bought our house the previous owner had built a considerably stable garage. Thus it does not block out much cold. I would say that the temperature depends on the weather, maybe one or two degrees above the temperature. Is there a specific temperature at which I should work with the bacteria?

Okay, so those two papers aren't related to my MFC project and I do not have to read them, correct?

What do you think of the terms I found on Wikipedia?

Lastly, I was reading the MFC article from Wikipedia (http://en.wikipedia.org/wiki/Microbial_fuel_cell) and scrolled down to the "See Also" section. There are links to other Wikipedia articles with terms I haven't studied at all. About all of them relate to hydrogen - why is that? Do you recommend I study those terms?

[donnahardy2]

Hi Irregular,

Good. Your Dad is a mechanical engineer and he can give you advice on the design and construction of the MFC; an electrical engineer can advise you about the electrical circuitry. Why don't you give the design you are planning to use to both engineers and ask for suggestions on the materials, construction, and possible problems you might encounter? They might be able to suggest using alternative materials that would work better or be less expensive.

Most of the temperatures we've seen in the literature range from 20 to 30 degrees Centigrade. The one paper that cited an optimum temperature when using Rhodopherax ferrireducens was 25 degrees C, which a 77 degrees F, or like a room that is a little too warm. Generally, for every 10 degree C change in temperature up to the optimum temperature the rate of bacterial growth doubles. If the temperature is too high, the bacteria die; it it's too low, they just slow down. So if your temperature was significantly below 20 degrees Centigrade, your bacteria might not be able to grow and metabolize quickly enough to generate electrons. What temperature range do you expect in your garage this month? Is there any way to add a little heat?

You are correct; you don't have to read the hydrogen fuel cell paper. A hydrogen fuel cell is a type of microbial fuel cell that yields hydrogen gas; you are making one that will generate electricity. The other paper is a review paper and you have the information available in other papers. You should be aware of the different types of microbial fuel cells, but just concentrate on the papers that relate to your project. You can ignore all references about hydrogen fuel cells for now.

The following link from the Wikipedia site contains a very clear explanation of why Rhodopherax works better than other bacteria to generate electrons in an MFC:

http://www.scq.ubc.ca/microbial-fuel-ce ... ireducens/

How are you doing on collecting materials for your MFC?

Donna Hardy

[irregular]

Hello!

I will talk to my dad about materials, construction and possible problems as you mentioned. I will ask him if it is possible if he can contact an electrical engineer to look at the electrical circuit.

Hmm.. that's an interesting point. I will discuss the temperature issue with my parents and inform you of my decision. Thanks!

Thanks for clarifying my hydrogen fuel cell confusion Additionally, I printed the article on the bacteria to read and refer to. Unfortunately I will not be able to identify my bacteria. If I could, however, I would definitely consider using this bacteria and altering my MFC to suit the bacteria. So I guess this article will help me in thinking about my MFC itself and the results (efficiency, for example),correct?

A few materials needed for the MFC will have to be researched and purchased. For example, I will probably have to order the carbon cloth online. However, basic materials such as the multimeter, alligator clips, anode/cathodes materials, fish tank, etc. will be easier to purchase. I will think about whether using boxes, bottles or jars will be better for my experiment (for the anode/cathode).

Wow, indeed background research is essential, extremely beneficial and helpful. I am still reading more and more information based on the MFC and key experiment terms. Do you recommend any mathematical concepts which I should study? For example, the Rhodopherax MFC article quotes:

The stoichiometry of glucose oxidation and iron reduction is as follows:

Oh my, how much can I ever thank you for all your help!?!?!?

EDIT: I found a Final Report a student wrote based on single-chambered MFCs. I am not looking at his analysis, but I looked at the part which he classified as Literature Review in his report. Would this be the background research section? As you scroll down, he mentions many mathematical equations which I am unfamiliar with. Do they relate to my subject? He mentions topics such as " Root-Finding Numerical Methods", "Parameter Estimation", the "Monod model", for example.

Report link: http://www.engr.psu.edu/ce/enve/logan/b ... roject.pdf

[MelissaB]

Hi,

I can't get at the PDF right now; my computer died and I am on an exceedingly old one that can't really handle PDFs. However:

The "equation" you saw in the other paper is an example of something called stoichiometry. It's a method chemists use to keep track of molecules. For example, what this particular stoichiometric equation says is that if you take a molecule of glucose (C6H12O2) and combine it with six molecules of water (H2O) and 24 molecules of a specific type of iron (Fe), the reaction they are studying results in the production of carbon dioxide (CO2), water, and a slightly different type of iron.

I think that this is probably a little advanced for your age category--most people do not learn this until a chemistry class in high school.

As to the PDF you mentioned, as I said, I cannot see it, but a parameter estimate makes me think that they created a mathematical model to simulate some process that was going on in the fuel cell. Again, I think that this is a little beyond your grade level and that you do not need to worry too much about this; if I were judging a science fair, I would definitely not expect you to be able to do anything like that in middle school.

However, if you want to know more, we would be happy to help--it's not as if I'm not saying don't learn it; instead, I don't want you to feel as if your project will be unsuccessful if you don't understand stoichiometry or mathematical modeling as a middle-schooler .

[donnahardy2]

Hi Irregular,

You did a great job in advising Kirby on his last minute project! That was very kind of you to spend your time to share your experience in planning science fair projects. I think you have a great future as a science buddies advisor.

If you get a chance to talk or e-mail the electrical engineer, ask for ideas on how to lower the resistance of the circuit. This is a common problem reported in many of the papers we have been reading and high resistance limits the usefulness of many MFC’s. It’s also why the soldering technique is important; to make sure the electrical connections are secure. Ohm’s law of electricity explains the why low resistance is preferred in an MFC:

http://en.wikipedia.org/wiki/Ohm's_law

Look at the formula: I (current) = V(voltage)/R (resistance)

You will be measuring current and voltage with your multimeter. You can see that if the electrical resistance is high, then the current (flow of electrons) is reduced, so ideally you want a low resistance in your circuit. An electrical engineer would be able to tell you if what you could do to have the lowest possible resistance.

You should order the carbon cloth as soon as possible to make sure this item does not hold up your project. You might want to telephone the company and make sure the item is in stock and will ship immediately. Try not to order something that is on backorder.

What about a mediator? What are you planning to use to mediate the transfer of electrons from the bacteria to the salt bridge?

The equation for glucose oxidation and iron reduction definitely applies to your project, but the equation for your apparatus might feature a different electron donor and acceptor. This particular equation shows how electrons are generated from the reduction of Fe III to Fe II, and this would apply to your project if you were to add FeIII (iron chloride) to the anaerobic chamber. According to the references, adding iron helps increase the flow of electrons, but it is used up and has to be regenerated. You will need an equation to describe whatever electron acceptor you will be using and I will explain this in more detail very soon.

The final report from one of Bruce Logan’s students contains some useful equations for evaluating an MFC and would be optional for you. For your project I think that Ohm’s law will be sufficient to describe and measure your results. However, if you are interested and if you have time after you complete your project, you can come back to this article and see if you want to try applying any of the equations to your system.

Donna Hardy

[deleted-71588]

I just read the Science Buddies project and it has a few flaws in terms of electrical measurements.

I haven't gone through this entire thread to see what your hypothesis is and what materials you are going to be using.

If you are going to be running multiple samples concurrently, my first thought would be to utilize your meter to measure current and when the meter is not connected to a given apparatus, to short the annode and cathode leads together.

The impedance (resistance) of your DVM on a millivolt scale can easily be higher or lower than the impedance of the apparatus and should different samples have different impedances that are higher and lower than the impedance of your meter, huge measurement errors will result.

By using the DVM on a DC micro or milli Amp scale, the meter is gauranteed to have a lower impedance than any of your samples.

In any case, you need to have some "load" between the annode and cathode at all times during your experiment (except for brief periods when you are putting the meter in and out of the circuit.

If you fail to provide an external electron path between the annode and the cathode chambers, the microbial activity in the annode chamber could easily drive the chemistry to a different state. Understanding all of the anerobic microbial organic chemistry possibilities in your samples is well beyond any of our abilities (expert and you alike) because we can't know exactly what is in your samples without analyzing them which is well beyond your time and budget.

You can reduce the impedance of the cathode chamber by adding salt; however, that will likely kill any microbial activity in the cathode chamber so it depends on exactly what you are testing on whether that is a good or bad idea. Living cells need the chemistry of surrounding fluid to be isotonic with the intracellular fluid to prevent the cell walls from bursting from ionic pressure.

[irregular]

Hello Melissa, Donna and Craig!

Thank you so much for your helpful advice! I am nearly finished my background research and have printed all of your replies. Once I finish background reading, I will be able to understand some concepts/terms better and will reply back to your comments and concerns.

Thanks for your patience, sorry for the late reply!