Triboelectric Generator: Walk And You Can Produce Energy

Everyone knows that Piezo-electric crystals can produce an electric charge due to pressure on its surfaces. Triboelectric effect is some thing similar to this. In this effect, an electric charge is generated through friction between two different materials. Researchers at the Georgia Institute of Technology have taken this effect a step further and have come up with the triboelectric generator. They introduced a gap between the two surfaces and the charges produced give rise to a voltage drop and a current flow. Thus the charge developed can be harnessed. It is important that the two surfaces be different materials. This generator can be used to produce electricity from activities such as walking.

#-Link-Snipped-#

If the two surfaces, say polyester and polydimethylsiloxane (PDMS) rub against each other, the former donates electrons and the latter accepts electrons. Their separation causes the positive and electric charges to separate. As you know, this is the dipole movement. And when an electrical load is introduced between them, it causes the current to flow.

This can be used to produce a “sensitive self-powered active pressure sensor”. They can detect pressure as low as around 13 millipascals. They can detect contact with something as small as a feather.  Also, since they can be made 75% transparent, it can be used as a touch screen that can power it self. So that kind of a touch screen will not draw power from your battery for its operation.

The current generated can be increased by using micro-patterned surfaces. After much testing, the team found out that the surfaces patterned with pyramids were the most efficient and generated the most current as much as 18 volts at about 0.13 microamps per square centimeter. The reason why this structure was more efficient was the presence of air voids. The air voids help in improving the capacitance change and facilitating charge separation.

The simplicity and reduced cost of process can allow large scale production and practical applications. Friction is every where and so this process can be used in many applications. These generators are robust and work well even after days of use or 100,000 cycles of operation. Now that they can produce the current, the team’s next target is to come up with a technique to store the current thus produced.

Via: #-Link-Snipped-#