Fiber-based thermoelectric generators and their substrate materials

Fiber-based thermoelectric generators are a versatile development in the field of power generation that has numerous applications in waste heat recovery and wearable technology. They differ from conventional thermoelectric generators, due to their flexible nature, which allows them to conform to the shapes of irregular surfaces and efficiently convert thermal energy to electrical energy, however, they retain the merits of reliability and longevity of their conventional counterparts. Their flexibility comes from the substrate onto which the thermoelectric materials are coated, several materials have been used as substrates, and of these materials, some have been more suitable for use than others. This review aims to assess the properties of some of these materials, their shapes, as well as material treatment methods that if implemented would enhance substrate surface properties by up to 139%, as well as changes to the shape and structure of fibers which would significantly enhance the thermoelectric performance and the longevity of fiber-based thermoelectric generators.