Make Your Own Hydrogen Fuel Cell

A fuel cell is a cell that produces an electric current directly from a chemical reaction.

hydrogen fuel cell is capable of producing electricity without any pollution because the only byproduct is pure water.

 

Hydrogen fuel cells are the most common, used in spacecraft and other areas where there is a specific need for a clean and efficient power source is needed. We will show you how you can make a hydrogen fuel cell yourself in about 10 minutes. When finished you will be able to show how hydrogen and oxygen can combine to produce clean electricity.

 

Items needed:

 

  • One foot of platinum coated nickel wire, or pure platinum wire
  • A popsicle stick or similar sized piece of wood or plastic
  • A 9 volt battery clip
  • A 9 volt battery
  • Transparent scotch tape
  • A glass of water
  • A volt meter

 

Cell Creation

First, cut the platinum wire into two six inch long pieces, and wind each piece into a little coil which will serve as the electrodes in your fuel cell. You can use a nail, ice pick or a coat hanger to form your coils.

 

Next, cut the leads of the battery clip in half and strip the insulation off the ends. When this is done, twist the ends of the bare wires onto the electrodes. Attach a positive wire from the battery clip and the positive cut wire to one electrode and do the same with the negative wires to the other electrode. The loose wires will be used later to connect to the volt meter.

 

Tape the electrodes securely to the popsicle stick, and then tape the popsicle stick securely to the glass of water. The electrodes should be almost completely submerged in the water.

 

Next, connect the red wire to the positive terminal of the voltmeter and the black wire to the negative terminal of the voltmeter. The voltmeter should read 0 volts, however, it may also read a small amount, such as 0.01 volts.

 

Fuel Cell Operation

Now that your fuel cell is complete to operate it you will need to cause bubbles of hydrogen to cling to one electrode, while oxygen bubbles cling to the other electrode. To do this, you simply touch the 9 volt battery to the battery clip. There is no need to actually clip the battery in place because it will only be needed for a second or two.

 

Touching the battery to the clip causes a process called electrolysis, which is when the hydrogen and oxygen in the water split and their bubbles form at the electrodes while the battery is attached.

 

When you remove the battery, if you weren’t using a platinum coated wire, you would expect to see the voltmeter read zero volts again because there is no longer the battery connected to it. However, in this case the platinum acts as a catalyst, allowing the hydrogen and oxygen to recombine.

 

The hydrolysis reaction reverses. The hydrogen and oxygen recombine to make water again and produce electricity.

 

In the beginning you will get a little over two volts from the fuel cell, as the bubbles pop and dissolve in the water or are used up by the reaction, the voltage drops, at first quickly, and then more slowly.


After a few minutes, the voltage declines a lot slower, because most of the recent decline is due to the gasses being used up in the reaction that produces the electricity.

Electric Charge Demonstration

Everything contains particles which have electrical charges, they can be positive, negative or neutral. Atoms are the basic building blocks of everything in the universe, and are made up of three components, electrons, protons and neutrons.

 

Electrons have a negative electric charge and are usually associated with electricity. Protons have a positive electric charge and neutrons are neutral, meaning they don’t have any electric charge. Atoms are usually constructed of the same number of protons and electrons. The negative charge of the electron cancels out the positive charge of the proton. This gives the atom a neutral charge.

 

The protons and neutrons are combined in the center part of the atom, called the nucleus. The electrons move rapidly around the outside of the nucleus. The nuclei of an atom never moves from one atom to the next, however, the electrons are free to move from atom to atom.

 

Electrons can travel from one object to another by contact alone. The reason for this is that some objects have a greater attraction to the electrons and will pull the them from objects that don’t have as strong of an attraction.

 

In this experiment use objects to charge another object and observe their interactions.

 

Materials needed:

 

  • Cellophane tape (invisible)
  • Paper clip which is unbent to form the shape of a “W” and a 12” long piece of string or thread tied in the middle. Crochet thread or kite string work well for this experiment.
  • Packing peanut or puffed wheat
  • 2 Plastic spoons
  • 2 – 8 X 10 inch pieces of Saran Wrap or other static plastic wrap
  • Cotton Clothing

 

Experiments:

 

Tape Experiment

 

Take two 4-5 inch pieces of tape and stick each of them to the edge of a table, leaving a ¼ inch tab hanging over the edge. Pull them off of the table, one in either hand and slowly bring the like sides together. Record whether they attract or repel.

 

Next, take two new pieces of tape of the same size and stick one to the table edge, again with a ¼ inch tab hanging over the edge. Then place the second piece of tape on top of the first with a ¼ inch tab hanging, unattached, over the edge. Pull the bottom piece of tape off of the table, but leave it still attached to the top piece of tape. Next, slowly pull the two pieces of tape apart. Now, bring the two like sides of each piece of tape close to each other without touching and record whether they attract or repel.

 

Spoon Experiment

 

Take the paper clip you shaped into the “W” on the string, tape the end of the string to the table so the paper clip hangs freely and unobstructed. Hold one of the spoons by the handle and rub the rest of it on the Saran Wrap, charging the spoon. Next, place the spoon into the paper clip so that it hangs freely. Be careful not to touch the charged end of the spoon.

 

Now, charge the other spoon in the same way and slowly bring the charged end of the second spoon to the charged end of the hanging spoon, without touching them and record whether then attract or repel.

 

Finally, rub the spoon you are holding on the piece of cotton clothing and bring it to the charged end of the hanging spoon, without touching, and record whether they attract or repel.

 

Packing Peanut


Repeat the spoon experiment, just this time use the packing peanut in the place of the paper clip. The peanut is neutral, meaning it doesn’t have a positive or a negative charge, so your outcome should be different. Record whether the spoons attract or repel in both experiments.

Lord Kelvin’s Thunderstorm

Lord Kelvin’s Thunderstorm is a type of electrostatic generator invented by British scientist William Thomson, better known as Lord Kelvin, in 1867. Kelvin referred to the device as his water-dropping condenser.

 

The device uses falling drops of water to generate voltage differences by using electrostatic induction, which occurs between interconnected, oppositely charged systems.

 

Water runs down from the top, with slightly positively-charged water attracted to the negative ring and slightly negative water attracted to the positive ring. The charged water flows through the ring and into a container.

 

The water traveling through the negative ring becomes H30+ and the water traveling through the positive ring becomes OH-. The charges then build in the ring connected to the container opposite it, attracting even more charge.

 

This results in a positive feedback loop. When the charge eventually reaches a certain threshold, a spark will cross the gap between the rings. The Kelvin Thunderstorm has been known to build a 20,000 volt charge with as few as 100 drops of water through each side in less than six seconds.

 

Keep in mind, this is done without any external power source, simply using the energy of the falling water drops. Electrostatic generators can be made to be very powerful.

 

The charge separation and build-up of electrical energy ultimately comes from the gravitational potential energy released when the water falls. The charged falling water does electrical work against the like-charged containers, converting gravitational potential energy into electrical potential energy, plus the kinetic energy.


The Kinetic energy is wasted as heat when the water drops land in the buckets, so when considered as an electric power generator the Kelvin machine is very efficient. The principle of operation is the same as with other forms of hydroelectric power.

How to Make an Electric Microcontroller Patch

A microcontroller is a small computer on a single integrated circuit containing a processor core, memory and programmable input/output peripherals. Microcontrollers are designed for embedded applications, in comparison to the microprocessors used in personal computers or other general purpose applications. Microcontrollers are used in a wide variety of automatically controlled products and devices.

 

Microcontrollers can contain several general purpose input/output pins (GPIO). Each pin will make your LED light perform different functions (steady, blinking or fading). By sewing a stitch from the specific pin to your LED light, you can program your microcontroller to perform the desired function.

 

In this article we will show you how to make your own microcontroller patch out of simple and inexpensive products.

 

Materials needed

  • Battery holder
  • Battery
  • LED light
  • Sewable microcontroller
  • Patch of sewable fabric

 

Tools needed

  • Sewing needle
  • Needle threader (if needed)
  • Conductive thread
  • Fabric scissors
  • Hot glue gun and glue sticks
  • Needle nose pliers

 

The microcontrollers should be pre-programmed to control the behavior of the LED. Curl the legs of the LED using needle nose pliers so that the LED can be sewn to the fabric.

 

If you are using a template, make sure you position the battery holder so that it lines up with the positive (+) and negative (-) holes.

 

Use a hot glue gun to glue the battery holder and sewable microcontroller to your patch. Be careful not to use too much glue so it doesn’t run onto any metal contacts.

 

Sew a stitch from the positive (+) hole on the battery holder to the positive (+) hole on the microcontroller. Next, sew from the negative (-) hole on the battery holder to the negative (-) hole on the microcontroller.

 

Figure out where you want to position your LED and hot glue it in place. Sew from the negative (-) hole on your microcontroller to the negative (-) side of your LED. Decide which action you would like your LED to perform (steady, blinking or fading). This will determine the hole in the microcontroller you will need to sew to from your LED.

 

Make sure there aren’t any loose pieces of thread on the back of your patch which could accidently touch and cause a short. Dab some hot glue on your knots to make sure they don’t unravel and short out.

 

Insert the battery into the battery holder with the “+” side facing up.

 

Webcast About Great Battery Experiments from Iron Science Teacher

In a parody of the cult Japanese TV program, “Iron Chef,” here is an excellent video where a live audience at the Exploratorium, in San Francisco, cheer on competitors in a fun science cook-off, where teachers compete for the sought-after title, “Iron Science Teacher.”

 

The Exploratorium’s Iron Science Teacher competition showcases science teachers as they create classroom activities using batteries.

 

Using a variety of items found at home, the teachers make several different experiments involving batteries. The first experiment, created by two teachers is a “Conducto-saurus”. Using a battery, aluminum foil, Christmas tree bulb and masking tape, the pair create what looks like a dinosaur. With two aluminum foil legs and a Christmas light tail, the teachers show how the bulb lights up when you touch the two legs together, closing the circuit.

 

They also demonstrate how, when you insert the legs of the experiment into water, there isn’t a connection. However, if you add salt to the water the bulb immediately lights up.

 

Other experiments include potato batteries fruit batteries and how our bodies can conduct an electric current which registers on an ammeter in different situations. This video is a few years old, but it does a great job of showing some easy and inexpensive experiments that can be done with kids at home.

 

Make a Blinking Top Hat

Arduino Pro Mini

The Blinking top hat was created by a couple of do-it-yourselfers to give as a gift at their friends’ engagement party. As the hat is tilted it lights up with rotating effects. The blinking top hat combines white LED strips, a small Arduino Pro mini and an accelerometer to obtain the really cool effect.

 

Parts needed

 

  • Arduino Pro Mini
  • Mini FET shield
  • ADXL335 Triple Axis Accelerometer
  • Rectangle AA battery holder
  • Power switch
  • Wire wrap wire
  • 12V strip LEDs

 

The light for the blinking top hat comes from regular white LED strips. They are driven by 12V, and are extremely bright. There are 16 strips in all, which are wired ingeniously in parallel so that the Arduino Pro Mini shield only has to deal with 8 channels.

 

Each strip has a self adhesive backing that holds the strip solidly (during extreme head maneuvers) to the top hat. The + and – connections are created with thin 30AWG wire wrap wire and poked through the fabric.

 

The Arduino Pro Mini 3.3 V/8MHz is the perfect size and has plenty of computing power to read the accelerometer and control 8 channels of LEDs. It uses a fraction of the power that the LEDs use and can be reprogrammed with an FTDI Basic for other cool lighting effects.

 

Each strip has 15 LEDs, which means it will use about (15 * 20) 300mA per strip when illuminated. This is way more than the ATmega328 can handle (about 20mA max) so the Mini FET Shield came in super handy. This shield allows a low voltage Arduino (3.3.Vs in the case of the top hat) to control much larger loads (12V and 300mA in the case of the LED strips).

 

Each of the 8 channels on the Mini FET shield can handle 2 amps, so the MOSFETs shouldn’t  even get warm. As previously mentioned, there are 16 LED strips, but they are wired in parallel so that you only need to control 8 channels to get a really cool effect.

 

Accelerometer

The hat uses the ADXL335, a classic workhorse with easy to read analog outputs for the three axes. But any solid state accelerometer, such as the ADXL345, the MMA7361, or the MMA8452Q, should work just fine.

 

The ADXL335 is old (3 years is ancient in the world of electronics), but it is very easy to read the analog voltages and convert them into 10-bit integers using Arduino. The real trick is doing the basic math to figure out how the top is moving. In general we take the three vectors (X, Y, and Z) and combine them into one vector.

 

Batteries

Because the LED strips run at 12V, the hat uses 8 AAs in two battery holders, to distribute the weight. When the batteries are fresh, we have a nominal voltage of 1.5V * 8 = 12V. The LEDs use a fair amount of juice, so lithium batteries were used to maximize the run time. In practice, the hat runs for tens of hours on a set of batteries, so alkalines could also be used. An in-line slide switch makes it easy to kill the power to the hat at the end of the night.

 

Wiring

The on/off switch provides power to the Arduino Pro Mini as well as power to the LED strips. There are 8 MOSFETs on the MiniFET that are individually controlled. You can use the shield or use 8 discrete MOSFETs. The accelerometer is wired into the analog inputs.

 

Vector Math

For the purpose of this project, you only need to be concerned with the movement of the hat (magnitude of movement), not direction:

 

A² + B² + C² = Z²

 

or in code:

 

float magnitude = sqrt((aX * aX) + (aY * aY) + (aZ * aZ)); //Combine all vectors

 

This is what the actual code looks like:

 

language:c
float avgMag = 0;
for(int x = 0 ; x < 8 ; x++)
{
aX = analogRead(accelX);
aY = analogRead(accelY);
aZ = analogRead(accelZ);

float magnitude = sqrt((aX * aX) + (aY * aY) + (aZ * aZ)); //Combine all vectors
avgMag += magnitude;
}
avgMag /= 8;

 

You will need to take 8 readings and average them together to reduce the noise. Next you will need to decide what to do with this magnitude reading.

 

For the purpose of The Blinking Top Hat you will need to have the LEDs spin fast when acceleration or movement is detected and then begin to slow the rotation as the movement of the hat slows. To do this, use an exponential growth equation to organically increase the time between channel changes (tBCC in the code).

 

Time delay between LED changes = A * xt

This is a basic exponential growth equation. The time between LED changes will increase exponentially with time based on a constant A and a growth rate x.

For example, if you want the LED strips to slow down across 3 or 4 seconds when the accelerometer stops detecting movement, then you will need to determine A and x.

You can determine the constant A by programming the hat to rotate in a circle and then see how small a delay the rotation could use before your eyes couldn’t discern the difference. 10-20ms between a step to the next LED strip looked pretty awesome. Anything less than 10ms just turns into a blur.

To determine the growth rate x, a spreadsheet was used to find that a growth rate of 1.00086 would cause the delay to increase to over 500ms within 3.5 seconds.

 

Soft PWM

You may find that the LED is too bright. You can reduce the brightness by pulse-width-modulating (PWM) the 8 channels. If you reduce the PWM ratio, then the LED strips should be less bright and you should be able to extend the battery life. The problem is that the Arduino Pro Mini only has 6 PWM channels, not enough to run all 8.

language:c
SoftPWMSetPercent(chan0, brightLevel);

This simple function allows you to set a given LED strip to a brightness level between 0 (off) and 99 (full brightness). Although, testing has shown that a brightness level of 9% was bright enough, without being overbearing.

The Blinking Top Hat is a fantastic experiment that will amaze everyone.

Making a Scribbling Machine

Making a scribbling machine is a great way to experiment with the erratic movement of an offset motor. Basically, a Scribbling Machine, is a motorized gadget that moves in erratic ways and leaves a colorful trail which traces its path.

 

A scribbling machine is made from simple materials and demonstrates the erratic motion produced by an offset motor.

 

You can use harvested motors and switches from old, discarded toys and electronics from everyday objects like strawberry baskets and milk cartons. You can experiment with different lengths and weight of the eccentric motors, test various drawing tools, experiment with materials used for the base and increase and decrease the speed of the motors. You will be amazed at the different motions and patterns you can create.

 

Items needed:

 

Motor (1.5v – 3v)

Battery (AA or AAA)

Electrical wire

Wire stripper

Masking tape

Art scraps (cardboard, milk carton, strawberry basket)

Hot glue stick

Markers or pens

 

Assembly

Strip the ends of the electrical wire and connect the motor to the battery using masking tape to secure the wires.

 

Experiment with ways to offset the motor (try clay, wood or a hot glue stick). Find out what happens when you change the weight on the offset motor, as well as the arm on the motor.

 

Build a base and attach the offset motor (try using foam board, a milk carton, a strawberry basket or other household items. Make sure there is enough clearance for your offset motor to spin.

 

Attach markers or pens to trace the jittering movement of your Scribbling Machine. You might want to try using a steel wire to attach the markers and pens because it makes them more responsive to the movement of the motor. You can experiment with your own designs.

 

Now turn it on and see what kind of designs you create!

 

This experiment is a great example of a low-tech activity that works well on its own, but can be made more interactive when you use sensors and microcontrollers to make it more complex.

 

Cell phones and pagers use offset motors when they vibrate. You can harvest a motor from a discarded phone or pager, then connect it to a battery the same way you did for your Scribbling Machine. These little motors can be used for all kinds of interesting projects.


Have fun with it, and check out all of the other great electrical experiments on our site that are easy and inexpensive to do at home.