UK scientists develop optimum piezoelectric energy harvesters

Mar 02, 2012

Scientists working as part of the Metrology for Energy Harvesting Project have developed a new model to deliver the maximum power output for piezoelectric energy harvesters.

Piezoelectric materials convert electrical energy into a strain (or vice-versa). The best known use of is for medical ultrasound.

Piezoelectric energy harvesters utilise energy from unwanted , such as the rattling of an air conditioning duct or the movement of a bridge with passing traffic. Power levels are small, usually a few milli-watts or less, but the scavenged energy could be used to power autonomous devices such as wireless sensors.

Piezoelectric energy harvesters are typically vibrating cantilevers, covered with a piezoelectric layer that converts to an electrical charge to power devices. Most developers cover the entire length of the cantilever with piezoelectric material in an attempt to maximise the .

However, scientists based at the UK's at National Physical Laboratory, one of seven national measurement institutes involved in the European Metrology Research Programme funded project have discovered that this approach is counterproductive. Their research shows that due to the charge redistribution across the there is an internal loss of power of up to 25% of potential output. To counter this the team has developed a model to show that more energy can be converted if the beam is only covered with piezoelectric for two thirds of its length.

Current piezoelectric energy harvesting devices are used in applications such as wireless and battery-less light switches, and sensors. However, their potential applications range from the predictive maintenance of any moving or rotating machine parts, to electronic devices that harvest their own wasted operational energy to be more energy efficient.

Harvesting energy that would otherwise be wasted is key to meeting future energy demands while reducing carbon emissions. This energy can come from light, heat, movement or vibrations.

Markys Cain, Knowledge Leader at NPL, said:

"The energy harvesting market was worth $605 million in 2010 but is predicted to reach $4.4 billion by the end of this decade. For the market to reach its true potential we need to develop the products that can guarantee a greater energy yield and drive industrial adoption of energy harvesting products. The work undertaken by the Functional Materials Group at NPL will do exactly that, providing a model for more efficient piezoelectric energy harvesting methods."

The research was originally published in Applied Physics Letters 100, 073901 (2012).

Explore further: New filter could advance terahertz data transmission

Related Stories

Raiders of the lost amp

Jul 05, 2011

Energy harvesting is a process that captures energy that would otherwise be lost as heat, light, sound, vibration or motion. It can use this captured energy to improve the efficiency of existing systems or even to power new ...

Giant piezoelectric effect to improve MEMS devices

Dec 02, 2011

Researchers in the Department of Materials Science and Engineering and the Materials Research Institute at Penn State are part of a multidisciplinary team of researchers from universities and national laboratories ...

Recommended for you

New filter could advance terahertz data transmission

23 hours ago

University of Utah engineers have discovered a new approach for designing filters capable of separating different frequencies in the terahertz spectrum, the next generation of communications bandwidth that ...

The super-resolution revolution

23 hours ago

Cambridge scientists are part of a resolution revolution. Building powerful instruments that shatter the physical limits of optical microscopy, they are beginning to watch molecular processes as they happen, ...

A new X-ray microscope for nanoscale imaging

Feb 27, 2015

Delivering the capability to image nanostructures and chemical reactions down to nanometer resolution requires a new class of x-ray microscope that can perform precision microscopy experiments using ultra-bright ...

Top-precision optical atomic clock starts ticking

Feb 26, 2015

A state-of-the-art optical atomic clock, collaboratively developed by scientists from the University of Warsaw, Jagiellonian University, and Nicolaus Copernicus University, is now "ticking away" at the National ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.