Energy transition will require us to make increasing use of new forms of energy. At the same time, existing energy must also be better utilised. Take waste heat from electronics. This not only allows parts to be damaged but also lets precious energy disappear into thin air. Scientists from America have developed a thin film layer that can capture residual heat and recycle it into energy. They see possible applications for computers, cars or manufacturing environments.
Many of the existing systems for using waste heat operate on the thermoelectric principle. That is, electricity is generated by the temperature difference between two sides of a material. This works fine for some applications, but does not perform as well when the temperature difference between the hot and cold sides is small.
The new material works on the basis of so-called pyroelectric energy conversion. This technique also lends itself to lower temperatures (less than 100° C) and gradual changes. This makes it ideal for use in electronics.
Meanwhile, scientists have already built prototypes of devices with a 50-100 nanometre thick film layer. These devices achieved an energy density of 1.06 Joules per cm3, a power density of 526 W per cm3 and a Carnot efficiency of 19% (a measure of the efficiency with which heat is converted into electricity). Through their research into pyroelectricity, the scientists hope to arrive at better designs for electronics and conductive films can be adapted for individual systems.
