Materials scientists from Singapore have developed a textile that is not only waterproof and stretchy, but can also charge batteries. The movements of the wearers of the fabric should provide energy for this.
A 3-cm by 4-cm patch of this material compresses enough energy for 100 light-emitting diodes, according to Jiang Feng, a graduate student with research director Lee Pooi See. “We think it can be integrated into T-shirts and shoe soles to collect energy from the body’s smallest movements and generate power for mobile devices,” she says.
Small body movements are enough
The fabric developed by the NTU team converts vibrations generated by the smallest body movements in everyday life into electricity – in two ways: when it is pressed or squeezed (piezoelectricity) and when it comes into contact with other materials (triboelectric effect). ).
The experts first printed a stretchable electrode with an ink made of silver and styrene-ethylene-butylene-styrene. This is a rubbery material. They attached this electrode to a piece of nanofiber fabric, which consists of two main components: poly(vinylidene fluoride)-co-hexafluoropropylene (PVDFHPF), a polymer that generates electricity when compressed, bent or stretched, and lead-free perovskite crystals, which are mainly used in solar cells are used.
Only 2.34 watts per square meter
“Embedding perovskites in PVDF-HPF increases the electrical performance of the prototype. While these crystals are inherently brittle, their integration into the polymer gives them exceptional mechanical durability and flexibility,” says Feng. The result is a prototype that generates 2.34 watts per square meter of electricity – enough to power small electronic devices like LEDs and capacitors.
The fabric is durable and stable. Its electrical properties did not deteriorate after washing, folding and crumpling. “To our knowledge, this is the first hybrid perovskite-based power generator that is strong, stretchy, breathable, waterproof and at the same time capable of delivering excellent electrical output,” said Pooi See.