IIT-M shows technique to enhance output of piezoelectric materials

Piezoelectricity is the electric charge that accumulates in certain solid materials in response to applied mechanical stress.

Mandi: The Indian Institute of Technology Mandi (IIT-Mandi) on Monday said its researchers proposed a technique to enhance the power output of piezoelectric materials.

Piezoelectricity is the electric charge that accumulates in certain solid materials in response to applied mechanical stress.

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Mechanical stress is a measure of internal resistance exhibited by a body or material when an external force is applied to it.

Piezoelectric materials can be used in floor tiles to generate electricity from human walking, or on roads, where the weight from the vehicles can power road lights and signals.

In their study, published in the journal Engineering Reports, the research team have numerically studied piezoelectric materials — materials that interconvert mechanical energy and electrical energy.

They have proposed a new arrangement to enhance the electrical output of these materials when subjected to stress.

“Piezoelectric materials can generate electrical energy when a force is applied on them, and are thus extremely useful,” Rajeev Kumar, Associate Professor, School of Engineering, IIT Mandi, said in a statement.

“We have developed a technique known as “graded poling” to enhance the power output of piezoelectric materials by more than 100 times”, study researcher Dr. Rahul Vaish.

The researchers have used numerical techniques to utilize multiple mechanical stresses — bending, compressive and tensile stresses at the top and bottom of the piezoelectric cantilever beams and shear stresses in the mid-section — in order to significantly improve the electrical output.

The results of this study possible through the graded poling technique offers incentive for researchers to develop actual piezoelectric designs that implement the graded poling technique so that the applications can be realised.

The researchers recommend possible steps to achieve these designs in practice, such as partially connecting the right face of the sample to ground and top faces being applied with an electric potential.

The promise of generation of higher amounts of electrical energy from mechanical movement can potentially enable applications in which smart devices can be powered simply by human motion, the team said.

Other applications could include generating power from the soles of footwear equipped with these materials.

According to the researchers, piezoelectric materials can do the reverse as well generate mechanical motion in response to electrical energy.