If there weren’t already thousands of ways to produce a small amount of renewable current, researchers at the MIT have figured out that water vapor, coupled with newly developed polymer films can do the same, provided a few piezoelectric elements are attached to them. The team here has created a new polymer film that changes its shape after absorbing a small amount of water vapor allowing it to repeatedly somersault. Harnessing this motion could help drive robotic limbs or generate enough energy to power micro-electronic devices.
The new film is made using an interlocking network of two polymers. One of the polymers is hard but flexible to provide structural support and the other one is basically a soft gel that swells on absorbing water. Apart from generating energy, the researchers also saw that the material lift 380 times its own weight or transport 10 times its own weight by acting as a potent water-powered “mini-tractor”.
The mechanical energy generated by the materials can also be converted into electricity by coupling the film with piezoelectric materials that can convert mechanical stress to electricity. The system can generate about 5.6 nanowatts of power, which can be stored in capacitors to power small electronic devices such as temperature or humidity sensors.