Introduction: Bio Robot
Build you own Bio Robot using a super capacitor and vibration motor. Use common parts like paper clips for legs and beads for eyes or your own imagination. Charge the super capacitor for 20 seconds with two AA batteries and watch your Bio Robot go!
Step 1: Parts
2.7V 10 to 25 Farad Super Capacitor Ultra Super capacitor Ultra capacitor- at ebay
Note: 10f Super Capacitor will run about 5 minutes and 25f will run about 12 minutes (I used 25f).
6x10mm DC1.5-3V Micro Coreless Vibrating Vibrator Vibration DC Motor- at ebay
Paper clips, wire or pipe cleaner, beads
Glue gun and glue, two AA batteries
Step 2: Decide What to Use for Legs
You can use pipe cleaners, paper clips (this is what I used) or wire for legs. Measure all your legs and cut if needed so that they are all equal in length. Some legs can go around the super capacitor so that one wire can make two legs with one cut. If you are using paper clips, just unwind each clip as needed.
Step 3: Use a Glue Gun to Glue the Legs to the Super Capacitor
Using a glue gun, glue the legs evenly to the super capacitor. The one end of the super capacitor that has two wire leads (also called legs) must be kept free for charging your Bio Robot.
Step 4: Bend the Legs
Bend the Bio Robot legs that you made as desired and adjust each leg so that they all touch the surface at the same time when placed on a table.
Step 5: Tape the End of the Vibration Motor
Add a small temporary piece of tape to the end of the vibration motor that has a small half circle disk. This will prevent glue from getting on this disk or motor shaft. Any glue here might jam the motor.
Step 6: Glue the Vibration Motor to the Super Capacitor
Using a glue gun, glue the vibration motor onto the super capacitor with the wires facing towards the end of the super capacitor where the leads are.
Step 7: Connect the Wires From the Vibration Motor to the Super Capacitor
Tightly wrap one bare motor wire around one of the leads (legs) from the super capacitor and wrap the other bare wire from the motor to the other lead from the super capacitor. Make sure that the two bare wires don’t touch each other. You may need to strip more insulation off the end of the wire. You can solder these wires if you want to.
Step 8: Add Additional Parts As Desired
Continue gluing additional parts as desired. When all gluing is complete, remove the tape form the end of the vibration motor. Check that the motor turns freely.
Step 9: Make a Charging Station With Two AA Batteries
Building the charging station using AA batteries: Place two batteries side by side with – and + terminals of each battery at the top and at the bottom. Tape the two batteries together. Next, using a small piece of aluminum foil, place the foil over both terminals tightly at the top or bottom and tape. This will connect the batteries in series to create 3 volts. Or use a AA battery holder for two batteries instead.
You could also use a 3 volt solar panel for charging.
Step 10: Charge the Super Capacitor
Charge the super capacitor using the AA battery station. To do this, hold the super capacitor and Bio Robot with one hand and hold the battery station with your other hand. Connect the – side of the battery to the – side of the super capacitor and + to + sides of both at the same time and hold together for about 20 seconds. The + side of the super capacitor leg will be longer. The vibration motor should start turning and increase in speed as you charge. Don’t worry, you will not get shocked, but you may feel a little heat. Warning: Charging – to + may damage the super capacitor or degrade it. After charging the Bio Robot, it will run fast at first then gradually slow down and stop in about five minutes. You will then need to recharge the Bio Robot. You can recharge it over a million times! Charging over 20 seconds will not damage the super capacitor.
Optional: You could use a 3 volt solar panel with some alligator clips to charge the Bio Robot. Warning: Any voltage greater than 3 volts may destroy the super capacitor.
Place your Bio Robot on a smooth surface and it should start moving. It may go forward, backwards, or go around in circles. You might try different leg positions to see if moves differently. Stronger metal legs may cause some jumping action too.
Place the Bio Robot on a shoebox lid and hold the lid with both hands. See what happens and why is it louder?
Tape several soda straws on a table to make a track. Place your Bio Robot with the legs between the tracks. The Bio Robot should follow the track.
Step 11: Troubleshooting
· The battery pack is not producing about 3 volts. Make sure the batteries are properly connected and the foil tape is secure. Or use a AA battery holder.
· The tiny half circle disk at the end of the motor is jammed. If it is jammed, check that the disk is not hitting anything as you rotate it with your finger. If it is hitting something, move the end of the motor up so that the center disk turns freely. Also, if there is glue on the disk or on the motor shaft, you will need to remove it. Remember, the disk must turn freely when turning with your finger or when the motor is running.
· A broken or loose wire connection from the motor to the super capacitor. Make sure all connections are secure. Also, check that the two bare wires from the motor are not touching each other.
· When charging make sure you are connecting both sides of the battery to the super capacitor at the same time and with the – side of the battery to the – side of the super capacitor and + to +. The + side of the super capacitor will be have a square loop at the end of the lead or leg. The motor should start running even if you connect with a reverse connection. However, a reverse connection will degrade the super capacitor and the motor will not run as long.
· The Bio Robot has run out of power. Recharge the super capacitor.
Step 12: The STEM Behind the Project
The STEM behind the project:
Science: A Bio Robot is a type of robot that is life like. Bio means life as used here. Robots are used to help us to do all kinds of things to make our life easier and safer. We use all types of electrical and mechanical parts to make robots and we can program them to do what we want. The main parts used in your Bio Robot are the super capacitor and vibration motor.
A super capacitor is an electrical device that can typically store 10 to 100 times more energy per unit volume than an electrolytic capacitor. They also accept and deliver charge much faster than batteries, and tolerate many more charge and discharge cycles than rechargeable batteries. They are, however, 10 times larger than conventional batteries for a given charge. Super capacitors are similar to a battery because they can store and release electrical energy. When you charge the super capacitor on the Bio Robot using AA battery pair, electrons move from the battery to the two plates inside the super capacitor. These plates are separated by a non-conductive electrolyte material and separated by a very thin insulator (usually, carbon, paper or plastic). The negative terminal is accepting all of the electrons produced by the AA batteries until the super capacitor is fully charged which will be about 20 seconds. At the same time, the plate attached to the positive terminal is losing all of its electrons. The charged super capacitor has a concentration of electrons (a charge) on the surface of the negative plate. This charge separation creates a potential (voltage!) between the two plates. This charge will last about 5 minutes then your Bio Robot will stop working and your will need the recharge it.
The vibration motor is the same type motor used in cell phones. They are also called Eccentric Rotating Mass motor or ERM. The motor will have an offset (non-symmetric) mass attached to the shaft. As the ERM rotates, a centripetal force is created by the offset mass. This mass is asymmetric causing a net centrifugal force. This will cause a displacement of the motor. The high number of revolutions per minutes will cause the motor to be constantly displaced by these asymmetric forces. The vibration is the result of this repeated displacement. When the vibration motor is mounted to the Bio Robot, this vibration is transferred to the legs causing movement. Vibration will also cause sound which we can hear. Lots of things vibrate like your own vocal cords that allow you to make speech. Another example is the speaker inside your cell phone that vibrates to make sound. Sound waves travel through air at about 332 meters per second.
Technology: When you designed and built your Bio Robot you made something that could be used as a toy.
It also helped you learn several things that maybe you didn’t know before. Engineers are also producing ensembles of small, insect-like robots that cooperatively perform jobs that might be difficult, dangerous, or tedious for humans to carry out. As in nature, these robotic systems tend to be decentralized, composed of agents doing simple things that add up to communal achievements. Although the current price tags per unit are generally in the triple digits, developers hope one day to make the devices so inexpensive that some robots could be lost or damaged without jeopardizing the entire mission.
Engineering: When you look all around you can see examples of what someone designed. It can be as simple as a paper cup. When you build something, you think about what parts are available and how they will work together to make something new. Often times, you will need to know the specifications of the part which will be listed when you buy it. Using the parts you had for your Bio Robot, you designed it the way you wanted. Sometimes the parts don’t work well together and you have to try something else. Thomas Edison and his lab associates, called "Muckers," conducted thousands of experiments to develop the electric light bulb. There are all kinds of things that haven’t been made yet, maybe you will have a great idea someday that will help people or make their lives better.
Math: You used math when you made your Bio Robot. Math is also used when people design anything.
We can also use math to measure the frequency of the vibration motor. Frequency is the rate at which something occurs or is repeated over a particular period of time or in a given sample. The rate at which a vibration occurs constitutes a wave, either in a material (as in sound waves), or in an electromagnetic field (as in radio waves and light), usually measured per second. The vibration motor you used will vibrate at about 10 times a second when you start to change the super capacitor to about 200 times per second when fully charged. We also need to know how much the maximum voltage the super capacitor can use. If we use too much voltage, the super capacitor will be destroyed. When you begin charging the super capacitor it is receiving a small voltage which is why the vibration motor starts running slow. When it reaches about 3 volts, it runs much faster. You could measure the voltage and frequency and make a graph. We can also measure the time used before the Bio Robot stops working and how far it can go.