Harvesting the wasted energy that is bound to appear in all possible manifestations of energy transaction is key in sustainable engineering, but the complexity of manufacturing solid-state devices that are adequately effective to be feasible has troubled engineers during this past decade. Researchers at the Institute of Materials Science of Barcelona have presented their own take on sustainable and recyclable thermoelectrics that address the cost problems and simplify their manufacturing.
More specifically, the manufacturing term has been taken out of the picture entirely and got replaced by cultivated farming. Bacteria produce a porous nanocellulose matrix that contains a network of carbon nanotubes that would otherwise be ten times more costly to make. In addition to the cost benefits, the resulting carbon nanotube films feature chemical stability that goes up to 250 degrees Celsius and can be wrapped around heat sources to produce electrical energy.
Since no toxic substances are used in the process (conductive material, sugar, carbon nanotubes), the films can be safely decomposed through an enzymatic process, recycled, and reused for new cultivations. The most valuable of the substances are the carbon nanotubes, and those are recovered through the process at a high rate. It is this element that enables the electrical percolation to take place in the film, so even a small amount of carbon nanotubes is key for the concept.
The possible applications for this thermoelectric bacterial cellulose are numerous, with the Barcelona-based researchers envisioning the powering of sensors for IoT applications and agricultural systems, or anything that is remote or impractical to power differently, such as smart wearables for example. The team claims that the room for improvement has already been identified, and if they achieve a significant energy conversion efficiency upgrade, we may even see hybrid photovoltaic-thermoelectric units based on this novel cellulose.