Researchers at Empa and ETH Zurich have managed to develop a material that works as a luminescent solar concentrator and can be applied even to textiles. This opens up many possibilities for producing energy directly where it is needed, ie for everyday use in electronics.
Our energy cravings are hard to satisfy, and even continue to grow as the supply of new gadgets increases. Moreover, we are almost always on the move and therefore constantly rely on a power source to recharge our smartphones, tablets and laptops.
In the future, power outlets could become obsolete, at least for this purpose. Electricity could be in our pockets – or in our clothes. A new polymer that is applied to textile fibers, jackets, T-shirts and the like could soon function as a solar collector and thus as a mobile source of energy.
How do you make luminescent materials flexible?
Materials capable of using indirect or ambient light for energy generation are already used in the solar industry. These materials contain special luminescent materials and are called “solar luminescent concentrators” or LSC for short.
The luminescent materials in the LSC capture diffuse ambient light and transmit its energy to the real solar cell, which then converts the light into electricity.
However, LSCs are currently only available in the form of rigid components, which are not suitable for use in textiles because they are neither flexible nor permeable to air and water vapor.
An interdisciplinary research team led by Luciano Boesel from the Laboratory for Membranes and Biomimetic Materials has now managed to incorporate several of these luminescent materials into a polymer that offers exactly this flexibility and air permeability.
Polymers with sophisticated properties
This new material is based on amphiphilic polymeric co-networks, or APCN for short, a polymer known for a long time in research and which is already available on the market in the form of silicone-hydrogel contact lenses.
The special properties of the polymer – air permeability and water vapor, as well as flexibility and stability – are also beneficial to the human eye and are based on special chemical properties.
“The reason why we chose exactly this polymer is the fact that we are able to incorporate two luminescent materials at the nano scale and let them interact with each other. There are, of course, other polymers, in which these materials could be integrated, but this would lead to aggregation, and energy production would not be possible, ”explains Boesel.
Shiny sunscreens for clothing
In collaboration with colleagues from two other Empa laboratories, Thin Films and Photovoltaics and Advanced Fibers, the Boesel team added two different luminescent materials to the gel tissue, turning it into a flexible solar concentrator.
As with large-scale (rigid) collectors, luminescent materials capture a much wider spectrum of light than is possible with conventional photovoltaics. The new solar concentrators can be applied to textile fibers without the textile material becoming brittle and susceptible to cracking or accumulation of water vapor in the form of perspiration.
Body-mounted solar concentrators offer a huge benefit for the growing energy demand, especially for portable devices.