Producing energy from vibrations is nothing new, and the world is always hungry for more clean energy. Engineers now have a new material that can convert simple mechanical vibrations all around it, to electricity. The electricity is enough to power most sensors on the Internet of Things ranging from spacecraft to pacemakers.
Engineers at the University of Toronto and the University of Waterloo have produced the material after decades of work. Their research has generated a novel compact electricity-generating system that they claim is reliable, low-cost, and green.
According to the researchers, their achievement will have a significant impact on social and economic levels, as it will reduce the reliance on non-renewable energy sources. They claim the world needs these energy-harvesting materials critically at this moment in time.
Energy harvesting technology produces small amounts of energy from external effects such as heat, light, and vibrations. For instance, an energy-harvesting device worn on the body could generate energy from body movements, such as from the legs or arm movements while walking. Most such devices produce enough energy to power personal health monitoring systems.
Based on the piezoelectric effect, the new material that the researchers have developed generates an electric current when there is pressure on it. Mechanical vibrations are one example of the type of pressure on the appropriate substance.
The piezoelectric effect is known and in use since 1880, and people have been using many piezoelectric materials like Rochelle salts and quartz. The technology has been in use for producing sonars, ultrasonic imaging, and microwave devices.
However, until now, most traditional piezoelectric materials in use in commercial devices have had a low finite capability for generating electricity. Moreover, most of these materials use Lead, which is detrimental to the environment and to human health as well.
The researchers solved both the above problems in one go. They grew a single large crystal of a molecular metal. This was a halide compound known as edabco copper chloride. For this, they used the Jahn-Teller effect, which is a well-understood concept in Chemistry, and offers a spontaneous geometric distortion in the crystal field.
The researchers proceeded to fabricate nanogenerators with the highly piezoelectric material they had produced. The nanogenerators had a significant power density and could harvest small mechanical vibrations in many dynamic circumstances involving those from automobile vehicles and even human motion. The nanogenerators neither used Lead nor needed non-renewable energy sources.
Each nanogenerator is just a shade smaller than an inch square, or 2.5 x 2.5 cm, and the thickness of a business card. It is possible to use them in various situations. They have a significant potential for powering sensors in vast arrays of electronic devices, such as those used by IoT or the Internet of Things, of which the world uses billions, and requires substantially more.
According to the researchers, the new material could have far-reaching consequences. For instance, the vibrations from an aircraft would be enough to power its systems for monitoring its various sensors. On the other side, vibrations from a person’s heartbeat could power their pacemaker, which can run without a battery.