For the first time a piezoelectric nanogenerator that is capable of generating electrical energy from diverse sources — mechanical, acoustic and wind — has been developed.
The device, fabricated by a team led by researchers from the Indian Institute of Technology (IIT) Kharagpur, has remarkable energy conversion efficiency of 62%, high output current (over 12 microampere), voltage (about 61.5 volt) and power density (over 9 mW per cubic cm).
The high voltage of nanogenerator can be used to light up about 100 commercially available microwatt LEDs.
The team used vitamin B2 to stabilise the beta phase of the piezoelectric polymer PVDF (polyvinylidene difluoride) and thereby enhance the piezoelectric performance. The results were published in Nano Energy.
The nanogenerator is also completely organic and biocompatible and so can be used for both vitro and in vivo applications.
The device was found to be highly sensitive to even very small external force such as touching, bending and air-flow.
When made into a thin film and placed on the wrist, the device was able to convert the biomechanical energy to electrical energy (0.15 volt). Same when it was placed on the throat and the person was speaking (0.5 volt), gargling (1.6 volt) or swallowing (0.29 volt).
When pressed by the heel, the device produced about 58 volts, and about 79 volts when placed under a running car. It could convert the pressure applied by water falling from a tap into electricity. When placed on speakers, the device was able to harvest sound energy.
Similarly, when placed on the lid of a table fan it could convert wind pressure into electricity. This technology is yet to be commercialized.
Reference- The Hindu, India Science Wire