Imagine a future where recharging your tablet could be as easy as typing a tweet—where portable electronic devices power themselves without ever plugging into the grid.

Researchers at RMIT University, Melbourne have assessed the capacity of piezoelectric films—thin layers that turn mechanical pressure into electricity—to do this.

The study is the first to evaluate how piezoelectric thin films, a thousandth of a millimetre thick, perform at the molecular level, precisely measuring the level of electrical voltage and current—and therefore, power—that could be generated.

“Piezoelectrics could be incorporated into running shoes to charge mobile phones, for instance, or enable laptops to be powered through typing or even used to convert blood pressure into a power source for pacemakers—essentially creating an everlasting battery,” says Dr Madhu Bhaskaran, one of the leaders of the project.

The work combines the potential of piezoelectrics with thin film technology, a cornerstone of microchip manufacturing. “The concept of energy harvesting using piezoelectric nanomaterials has already been demonstrated, but the materials involved can be complex and are poorly suited to mass production. Our study focused on thin film coatings because we believe they hold the only practical possibility of integrating piezoelectrics into existing electronic technology.”

The research, which was undertaken with colleagues at RMIT and the Australian National University in Canberra, has been published in the materials science journal, Advanced Functional Materials.

Photo: Electricity is generated as a force is applied to a piezoelectric film

Credit: Dr Daniel J. White

School of Electrical and Computer Engineering, RMIT University, Madhu Bhaskaran, madhu.bhaskaran@rmit.edu.au, http://bit.ly/oq2wNu