Mit Develops Polymer Film That Harvests Energy from Water Vapor

Researchers at Massachusetts Institute of Technology have developed a polymer film that helps in harvesting energy from water vapor as it winds in the presence of vapor particles.

The researchers at David H. Koch Institute for Integrative Cancer Research have developed this polymer. The energy generated by winding of such films can be used to power micro and nano electronic equipment. Besides, the innovation can be implemented to develop artificial muscles that can control robotic limbs. In fact, such films may be further improved in future and used as means of harvesting energy from water vapor. It is remarkable that this material does not alter the environmental composition around it.

The polymer film is 20µm thick and is made of 2 layers – one of polypyrrole and another of polyol borate. The former is hard and provides structural support to the film while the latter is a soft gel that absorbs water and expands. The polymer is sensitive to even little traces of water vapor. When it is exposed to vaporous air, the layer of polyol borate absorbs water gradient and tries to expand while the polypyrrole tries to hold the structure of the film intact. As a result, the upper layer that is of polypyrrole curls inwards due its relative rigidity and the expansion of polyol borate.

Harvests Energy from Water Vapor

The winding and curling of the polymer film may appear playful but the innovation is not the result of childish curiosity at all. The force exerted by the polymer film is astonishingly greater than one would expect. A single polymer film of 25 mg weight can lift 380 times its weight. That force is equivalent to that generated by electric actuators used in certain robotic limbs. This means that the film can be used to replace such actuators. Besides, they can function in regular environment as complete absence of water vapor is very rare. Indeed, this can become very optimal technique of harvesting energy from water vapor.

This material cannot only be used for harvesting the energy from water vapor but also as an efficient mini motor. Piezoelectric materials can be used with this polymer film for the generation of electricity. Presently, it can generate 5.6 nW of electricity that can run micro-electronic equipment. Remarkably, batteries need replacement or recharge but this material is capable of harvesting energy from water vapor that is always present in the environment. Thus, it can continue to function without any significant requirement of service or maintenance.

The innovation has expanded the scope of eco-friendly energy harvesting. It can be used with water, incorporated into garments (where sweat would drive it) and in numerous other ways. The world can only wait until reports on further research are revealed.