Abstract: A large amount of primary energy is consumed in power plants, automobiles, and industrial facilities. However, only about one‑third of this energy is effectively utilized, while most of the remainder is dissipated as waste heat. To recover this unused thermal energy, thermoelectric conversion systems have attracted increasing attention from the viewpoint of the Sustainable Development Goals (SDGs). Inorganic thermoelectric materials have been extensively studied and are already employed in practical applications such as space probes (e.g., Voyager and Cassini). In recent years, organic thermoelectric materials based on conducting polymers, carbon nanotubes, and their composites have attracted growing interest because of their advantages, including low‑cost fabrication, low toxicity, abundant raw materials, mechanical flexibility, and solution processability. For practical applications, the fabrication of free‑standing and flexible thermoelectric films that can be handled without substrates is particularly important. In this invited presentation, simple methods for fabricating free‑standing organic thermoelectric films are introduced, based on two representative systems. First, free‑standing conducting polymer films are demonstrated, which can be obtained simply by washing ionic‑liquid‑modified PEDOT:PSS films in water, enabling easy peeling from the substrate. Second, free‑standing single‑walled carbon nanotube films prepared by vacuum filtration of their dispersions are presented, without the use of polymer binders or complicated post‑treatments. These examples highlight that free‑standing and flexible thermoelectric films can be fabricated through remarkably simple processes, providing a practical platform for organic thermoelectric devices.

Keywords: Organic thermoelectrics, free-standing film, conducting polymers, carbon-nanotubes.

Biography: Dr. Ichiro Imae specializes in the development of novel π‑conjugated polymers and oligomers for sustainable materials aligned with the Sustainable Development Goals (SDGs). He received his B.E., M.E., and Ph.D. degrees from Osaka University. His research focuses on the design of organic dyes with well‑defined molecular structures and the development of composite materials incorporating carbon‑based substances such as graphene and carbon nanotubes, as well as silicon‑based materials including silica. He is also involved in the development of environmentally friendly fabrication techniques for energy‑related applications, including energy conversion devices (thermoelectric and photovoltaic cells), energy storage systems (lithium‑ion batteries), and display technologies. His research achievements have been recognized with several honors, including the CSJ Presentation Award and the Award for Encouragement of Research in Polymer Science from the Society of Polymer Science, Japan.