Solar cells from donuts and tea

It sounds unbelievable, but it is true. You can harvest most of what you need for a simple solar cell from powdered donuts and tea. Powdered donuts have nanoparticles of titanium dioxide which is a “high band gap semi conductor”.  This means that it can be used to make solar cells. The tea is simply used to dye the material so it can pick up the visible spectrum. The process is a bit too involved to be something you would just toss together in the field, but it’s cute nonetheless.

Comments

  1. Arthur Hall says:

    Hardly practical, but very educational!

  2. tRANIS says:

    “If he thought to himself, such a machine is a virtual impossibility, then it must logically be a finite improbability. So all I have to do in order to make one is to work out exactly how improbable it is, feed that into the finite improbability generator, give it a fresh cup of really hot tea…and turn it on!” ~Douglas Adams, The Hitchiker’s Guide to the Galaxy

    still very interesting
    ty

  3. Nacho says:

    Hey… the video doesn’t work!

  4. Patrick says:

    Hardly practical? The whole point of the video was showing how practical it could be. Every single piece of equipment can be found at home or at Wal-Mart. It may not have the same kind of power output of a PV or amorphous silicon cell but the idea of insanely cheap and accessible parts being turned into energy-saving devices has limitless practical applications.

  5. loupgarou21 says:

    @patrick
    please point to the conductive glass I can buy at walmart so I too may harness the awful power of the sun.

  6. Relaxalittle says:

    I can picture the headlines now… “Powdered donut prices soar”, “Donut shortage causing grief to millions”, “Cops on lookout for heavily armed donut thieves”

  7. rikiardo says:

    man, there is titanium dioxide in sun blocker also, so it must be checked out.

  8. BigD145 says:

    You can buy a tin of titanium dioxide paint tint from some hardware stores.

  9. djrussell says:

    interesting.

    did he remind anyone else of ashton kutcher?

  10. Tim says:

    Last I heard, the world’s supply of indium is running low…

  11. tony says:

    Great video. Wish I had an ammeter with the “lightning” setting.

  12. cyanide says:

    i’d rather use hair dye, indigo, henna, or some other dye than support starbucks. it’d also be a better idea to use black dye, i assume

  13. Will says:

    When I first started the video, my first reaction was a groan of displeasure at the style… which changed very quickly to delight.

    It turns out that actual, factual, interesting scientific content makes that self-depreciating style of video palatable, even pleasurable.

    English: It was good, me happy.

  14. sol says:

    I, too, would prefer a website with instructions and schematics and pictures and stuff instead of a youtube video, but the important thing is that random things connected to electricity can become semiconductors. This discovery happens again and again. The message to the experimenter is: “hook up random crap to electricity and see what happens,” rather than using your mental and physical energy to complain about other people’s experiments on a forum.

  15. hum4n says:

    @sol

    My dad died because he hooked up random crap to electricity. Except it was his crap, at 80,000 watts. While he was crapping it. Oh god don’t make me remember.

  16. cynic says:

    @sol
    unusual, unexpected or miscellaneous != random

    But yeah, it’s true. The unlikeliest of substances can contain or become semiconductors. I’d love it if, when a room temperature superconductor is discovered, it turns out to be something just as outwardly ordinary.

  17. TJHooker says:

    I’ve seen a metallic blue spray paint from a hardware store used on a peace of acrylic to produce a 2″ x 2″ 0.48V cell.

    There use to be people selling the instructions on the net too, but it all disappeared.

    I’m pretty sure it was the titanium dioxide in the paint. I think they used small wire and aluminum foil with silicon glue to wire it somehow.

    I wouldn’t bend the context of practicality on this method though; you can’t actually find some of that stuff at department stores etc.. Practical would be grocery store, gas station, or local hardware store.

  18. bueller says:
  19. Wraith says:

    mmmmm… donuts…
    I have to try this
    @bueller thanks for the link

  20. ross says:

    By strange coincidence I just bought about 10 packages of those doughnuts. Now I know what to do with them I guess.

  21. Blake Farrow says:

    Guy in video here –

    Can’t believe I made Hack A Day! So glad some people appreciated my peculiar sense of humour and my science. And GROAN @ the person above who mentioned ashton kutcher…

    I submitted a version of this video to an ACS contest, and could use all the support I can get:
    tinyurl.com/blake-acsnano

  22. Roger says:

    Titanium dioxide is used in other foodstuffs too, like smarties for the white inner coating over the chocolate.

  23. dubmuffin says:

    @roger or possible roger detractors:

    Smarties do in fact have chocolate in them. Not those nauseating discs of confectioners sugar and ascorbic acid sold as candy stateside, but rather the delicious better-than-an-m&m candy coated chocolate sold in more civilized parts of the world…

  24. atomic says:

    the future of solar energy begins with breakfast

  25. jason says:

    YASHAD (Yet Another Stolen HackADay)

    This method has been around since (at least!) May of 2006 when I found it here:

    http://www.solideas.com/solrcell/english.html

    Does no one cite sources anymore?

  26. zombie_funk says:

    that looks like the kitchen from fight club…

  27. Eric says:

    Really, you aren’t using the donuts at all… Just the powdered sugar. Presumably, any kind of tea- similar to that one, would also work- So you really go from false advertising, to free advertising for a company like Starbucks. Nice science fair project, schmuck.

  28. Eric says:

    Needless to say, you can’t EAT solar cells!

  29. danman says:

    your all a bunch a cynics. sheesh. Good job on the educational video dude!

  30. Cheese says:

    Anyone else notice the fake lens flare towards the end? I call shenanigans!

  31. Blake Farrow says:

    too all the cynics:

    this is a very well known method for making solar cells, published as far back as the 70s by Graetzel’s group out of switzerland. The whole donuts and tea thing is just a way of making it a bit more catchy and interesting to the masses. And anything that makes science more catchy and interesting is good, amirite?

    fake lens flare was all me… I didn’t think it was very clear that it was a sunny window, so I added it there for kicks. the lens flare button was right beside the lightning one, had to use it. We have much more quantitative results done in solar simulators using much more reliable equipment. An open window is just easier to come by.

  32. Cheese says:

    ah ha! so it -was- fake lens flare. id love to see a demonstration of this in person some day, though i’m not sure where one acquires ‘conductive glass’

  33. random thoughts says:

    conductive glass… I’m thinking all glass must be conductive, at least to some extent. My father tells me a story of how his mother was working in the kitchen when lightning came through the glass window, circled the kitchen and left via another glass window. I know it sounds weird but there ya go.

  34. Iv says:

    @random thoughts : glass is used as an insulator in various high voltage stuff, so I would say that conductive glass is not your common type of glass. What your father witnessed was probably ball lightning, a not-so-rare occurrence of lightning. (5% of US population seems to have witnessed one)

  35. Oren Beck says:

    Photocopier/high speed scanners tended to use a slightly to moderately conductive coated platen glass if they had ADF or RADF document handlers. As the static charge was wreaking havoc of several sorts. Paper showed “stiction” to the glass and dust was electrostatic field drawn to the glass. Scrapped platen glasses thus could be a not unobtanium source for conductive glass. Same with some “Low E” energy efficient window glasses. Metal Vapor Deposition is edgy for home tech folks but Mirror Silvering is not totally impossible if the chemical hazards are respected.

  36. anon says:

    hey eric, you’re a douche.

    see, i can state the obvious, too.

  37. Ian says:

    http://www.unitednuclear.com/chem.htm

    They sell Titanium Dioxide for relatively cheap…FYI.

  38. Solar Cells says:

    This is a useful article though… And you know, John Rogers, professor of science and materials engineering at the University of Illinois and his team have created a new method to produce flexible solar cells, transparent and extremely thin.

  39. This video is very educated. It’s always interesting to find out how he made that. I need to stop myself from trying to make this thing. What I’m really interesting is how to power air conditioner unit with solar energy? I know it power car, but why not air conditioner unit or my hot water.

  40. Andrew says:

    That is really crazy. The video was very informative. I found a great guide that describes how you can make your own panels here… it has videos too

    http://www.squidoo.com/Do_it_yourself_solar_panels

  41. hmm… microamps… Interesting, but this type of solar cell has been around for a while. Considering cost/time/effort/performance it is probably a lot easier to just buy a cheap surplus cell. But perhaps this is useful to motivate the children…

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