Instructables

Tiny AVR Microcontroller Runs on a Fruit Battery

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Some of the fruit and vegetables we eat can be used to make electricity. The electrolytes in many fruit and vegetables, together with electrodes made of various metals can be used to make primary cells. One of the most easily available vegetable, the ubiquitous lemon can be used to make a fruit cell together with copper and zinc electrodes. The terminal voltage produced by such a cell is about 0.9V. The amount of current produced by such a cell depends on the surface area of the electrodes in contact with the electrolyte as well as the quality/type of electrolyte.

The AVR microcontroller is a leading low power microcontroller that has been around for almost a decade now. Recently, new lower power devices have been added to the AVR family, called the PicoPower AVR microcontrollers.

In this instructable, we show how even the regular AVR devices can be set up and programmed to run off a fruit battery.
 
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Step 1: Preparing the Fruit Battery

For the battery, we need a few lemons for the electrolyte and pieces of copper and zinc to form the electrodes. For the copper, we just use a bare PCB and for the zinc, there are a few options: use galvanized nails or zinc strips. We chose to use zinc strips extracted from a 1.5V battery.

Start with a piece of bare PCB. The size of the PCB should be large enough so that you can create 3 or 4 islands on it. Each island will be used to place a half cut lemon on it.

Step 2: Prepare the Zinc Electrode

Next, open up a few 1.5V AA size cells for the zinc strips and clean it up with sand paper and solder wire to each strip.

Step 3: Arrange the Electrodes

On the bare copper PCB, cut islands with a file or hacksaw and solder the other end of the wire from the zinc strip to each copper island. For one cell, you need half a lemon and one island of copper and one zinc strip.
Lucianello2 years ago
I have never seen something like this! Maybe we will integrate more fruit in advanced technology?
Dumchicken3 years ago
at first glance i thot it was a tenis ball battery
lunus3 years ago
I know I'm probably a bit too serious, but when you look at the chemistry, the power doesn't come from the lemons or the apple juice--they just provide an ion conductive path between the metal plates (which are consumed) any energy produced in the battery must be more than countered by the energy expended in refining those metals. (to get technical, one metal will be consumed)
PSPerson5 years ago
energy crisis:solved Solution: Lemons!! lol thats pretty awesome!
that'd be a good thing to say at a press conference. "I have solved the energy crisis. lemons." and then just walk away without answering questions.
geeklord5 years ago
"One of the most easily available vegetable, the ubiquitous lemon can be used to make a fruit cell. " That sentance contradicts itself. I'm pretty sure that lemons are fruit......
yep.
"Do not reuse the lemons for any purpose after the experiment."

Can you use the lemons for the same experiment again?
ghzyy6 years ago
شكرا
Maarek6 years ago
I was wondering why you used HVSP to program this with the STK500 and not using the SPI (SCK, MISO, MOSI) on PB0-2?
zanshin7 years ago
great instructable!!!! i hope i'll have time to make this one
LasVegas7 years ago
In step 8, you could have easily put the video right in the Instructable by using the Video button. Other than that, pretty cool Instructable. Did you try other fruits/vegetables for power?
Gadre (author)  LasVegas7 years ago
We tried apple juice instead of the lemons and it was similar in performance. Havent tried any other combination yet, nor any other material for the electrodes.
LasVegas Gadre7 years ago
Zinc nails are easy to come by and work quite well for this type of application.
ARVash LasVegas7 years ago
Taters :3. (they work too :p)
alex_weber7 years ago
Very nice instructable. And I like the ATtiny13v, they can run on almost nothing. Can you reuse the copper and zink plates? Regards, Alex
Gadre (author)  alex_weber7 years ago
Can you reuse the cooper and zinc plates for making another battery? Yes, as long as it has not been physically damaged, it can be used again. We tried zinc plate from a used 1.5V AA cell and it was all worn out and had lots of holes in it and we cleaned it up and used it and even that worked OK.
CameronSS7 years ago
Cool system. How do you get the zinc strip from the batteries? I.e., is it the outside part, alkaline or carbon-zinc (I assume the latter), AAA, AA, C, or D? Good Instructable though.
Gadre (author)  CameronSS7 years ago
You are right, its the outside tube of carbon-zinc batteries. I believe it should be there for any size of battery although I extracted mine out of a AA cell.