Renewable Energy Technology Development

Renewable Energy Technology Development

A solar cell you can put in the wash

A team of scientists has developed a new type of ultra-thin photovoltaic device, coated on both sides with stretchable and waterproof films that can continue to provide electricity from sunlight even after being soaked in water or being stretched and compressed. This work could open the way to wearable solar cells, which will provide power to devices, such as health monitors incorporated into clothing. One of the requirements of the Internet of Things—referring to a world where devices of all sorts are connected to the Internet—is development of power sources for a host of devices, including devices that can be worn on the body. According to one of the researchers, these could include sensors that record heartbeats and body temperature, for example, providing early warning of medical problems. In the past, attempts have been made to create photovoltaics that could be incorporated into textiles, but typically they lacked at least one of the important properties—long-term stability in both air and water, energy efficiency, and robustness, including resistance to deformation—that are key to successful devices.

» For the present work, the members of the research group developed extremely thin and flexible organic photovoltaic cells, based on a material called PNTz4T, which they had developed during an earlier work.

» They deposited the device in an inverse architecture, which they had previously developed, onto a 1-um-thick parylene film. The ultrathin device was then placed onto acrylic-based elastomer and the top side of the device was coated with an identical elastomer, giving it a coating on both sides to prevent water infiltration.

» The elastomer, while allowing light to enter, prevented water and air from leaking into the cells, making them more long-lasting than previous experiments.