Scientists and researchers at MIT have come up with a new portable method of making power that uses heat and doesn’t require metals or toxic materials. The new method of generating power is based on a discovery made by MIT professor Michael Strano and co-workers in 2010. That team created a wire using small carbon nanotubes that is able to create an electrical current when the tube is progressively heated from one end to the other.
This is done by coating the nanotube wire with a combustible material and lighting it on one end like a fuse. Experiments conducted when the discovery was made generated tiny amounts of power, but current developments by Strano and other researchers have improved that efficiency by over a thousand times. With the improved efficiency, portable devices using this fuel coated carbon nanotube wire system, create energy that is equivalent to similar sized batteries.
The scientists working on the program note that it could be years before a commercial product using the tech is available. The basic effect that the team is working with sees a pulse of heat push electrons through the bundle of carbon nanotubes and carrying the electrons along with the heat. The team discovered that at times, the heat wave makes a single voltage, but at other times, it makes two different voltage regions.
The latest version of the new process is over 1% efficient in converting heat to energy, which seems very inefficient but is said to be “orders of magnitude” more efficient than before. The fuel that coats the nanotube wires in the experiment is sucrose, ordinary table sugar. The team does expect other combustion materials to generate higher efficiencies. The researchers also note that the new system can scale down for use in very small devices like wearables.