Researchers explore properties of the new material for better micro and nano piezoelectric devices.
Piezoelectric materials are used where vibration cancelling forces are required, as sensors or moving parts controlled by an electric signal in micrometer- and nanometer-sized devices, and for harvesting vibrational mechanical energy. Researchers from the Indian Institute of Technology Bombay (IIT Bombay) have proposed a new piezoelectric material with a better piezoelectric response than the commonly-used piezoelectric ceramics. Better response means that the proposed material can produce a large force from a small input electric signal.
The material used is called Graphene Reinforced Piezoelectric Composite (GRPC), which has fibers of PZT (lead zirconate titanate) and graphene nanoparticles embedded in an epoxy base. “We chose epoxy because it is easily available in the market and easy to work with,” says Prof. Susmita Naskar from IIT Bombay explaining their choice of material.
A good piezoelectric material has a high elastic coefficient. “The difference between a high and low elastic coefficient material is that between aluminum and rubber,” elaborates Prof. Naskar.
The team explored GRPC’s piezoelectric response and elastic coefficient using theoretical and computational models. The theoretical models used the properties of each constituent material and their proportions to calculate these properties. Also, some models take into account how the different components interacted with one another.
“Our computational models accounted for the different shapes and orientations of PZT fiber and graphene nanoparticles,” adds Dr. Kishor Balasaheb Shingare of IIT Bombay.
Researchers observed that both piezoelectric and elastic properties of GRPC were better than in conventional PZT-epoxy materials. The presence of graphene made deformation more difficult, and the GRPC devices could remain rigid and maintain their shape while also generating about double the force in the presence of electric fields.
Graphene is a very light material and yet extremely stiff. The main reason behind the improved effective properties (in GRPC) is due to graphene, which has a large surface area for interaction with PZT fiber and epoxy,” explains Dr. Shingare.
“We saw a significant increase in the piezoelectric response of GRPC in all directions. This could be useful in artificial muscles of biomedical devices that require movements in multiple directions,” comments Prof. Naskar.
According to the researchers, this study can help make more effective piezoelectric-based devices in the future.
The research has been published in the European Journal of Mechanics – A/Solids.