Generating Electricity from Jaw Movements

When it comes to generate some electrical charge with a unique ways, we will think about solar cell, biogas, sea wave, or wind turbin, or maybe any other source from our surrounding. But, have you ever imagine to generate electrical charge from one of your body's part? Most of you haven't, I'm sure about that. :) But, some researchers from Montreal's Sonomax-ÉTS Industrial Research Chair in In-ear Technologies (CRITIAS) at École de technologie supérieure have! They got an idea to harvest some electrical energy from jaw movements. You know, jaw movements is something that so familiar with our eating activities or when we speak. They said that this electrical charge may be used to power some medical implant device and other wearable devices.

Experiment Setup

The first question that maybe come out is why use jaw? Based on their research, the jaw has been recognized as one of the body parts with the most potential in this area, with estimates that the act of chewing during mealtime, for example, could produce around 7 mW of electricity. Pretty small tho, but with some twist in the future we will manage to generate more.

In an attempt to avoid all of that munching from going to waste, the team built a specialized chinstrap made from piezoelectric fiber composites (PFCs). PFC is a type of piezoelectric smart material that consists of integrated electrodes and an adhesive polymer matrix. The material is able to produce an electric charge when it stretches and is subjected to mechanical stress.

One of PFC example design, type : PZT (Piezoelectric zirconate titanate)

So how much charge are we talking exactly? Well, don't go ditching your phone chargers just yet. In testing where a subject chewed gum for 60 seconds, the strap's power output was around 10 µW, (out of a theoretical maximum of 18 µW). Research suggests it takes between 400,000 and 1,000,000 µW to make a phone call.

Basic and functional, but not exactly inconspicuous, the piezoelectric chinstrap is still a ways off becoming a viable product. The researchers do describe it more as a proof of concept rather than a device they actually expect people to wear, but they hope advances in this area could help wean us off expensive batteries that can be harmful to the environment.

"The power level we achieved is hardly sufficient for powering electrical devices at the moment; however, we can multiply the power output by adding more PFC layers to the chinstrap," says Aidin Delnavaz, one of the study's co-authors. "For example, 20 PFC layers, with a total thickness of 6 mm, would be able to power a 200 µW intelligent hearing protector.”

The team will now turn its attention to increasing the amount of piezoelectric elements in the strap to improve its energy harvesting capacity. It is hoped they can then use it to power small electronic devices and integrate a rechargeable battery for power management.

The research paper was published in the journal Smart Materials and Structures.

Source: Institute of Physics & gizmag.com