Review—Micro and Nano-Engineering Enabled New Generation of Thermoelectric Generator Devices and Applications

Abstract

As we are advancing our world to smart living, a critical challenge is increasingly pressing -increased energy demand. While we need mega power supplies for running data centers and other emerging applications, we also need instant small-scale power supply for trillions of electronics that we are using and will use in the age of Internet of Things (IoT) and Internet of Everything (IoE). Such power supplies must meet some parallel demands: sufficient energy supply in reliable, safe and affordable manner. In that regard, thermoelectric generators emerge as important renewable energy source with great potential to take advantage of the widely-abundant and normally-wasted thermal energy. Thanks to the advancements of nano-engineered materials, thermoelectric generators' (TEG) performance and feasibility are gradually improving. However, still innovative engineering solutions are scarce to sufficiently take the TEG performance and functionalities beyond the status-quo. Opportunities exist to integrate them with emerging fields and technologies such as wearable electronics, bio-integrated systems, cybernetics and others. This review will mainly focus on unorthodox but effective engineering solutions to notch up the overall performance of TEGs and broadening their application base. First, nanotechnology's influence in TEGs' development will be introduced, followed by a discussion on how the introduction of mechanically reconfigurable devices can shape up the emerging spectrum of novel TEG technologies. The technology-driven age we are currently in, have brought great advantages to establish a more comfortable and smarter living and it is leading the way for an even faster-growing development in all areas of science and engineering, but at the same time it brings an incredibly fast growing demand for energy. Current and future energy consumption mandate the need for alternative energy sources, with reduced environmental impact. Readily available solar and wind energies have lead the way as alternative energy sources to environmentally challenging fossil fuels.1 Moreover, thanks to more recent developments in thermoelectric (TE) materials and devices, the possibility of making a better use of the widely abundant and normally wasted thermal energy, has becoming a popular and feasible alternative.2 More importantly, thermal waste has become a very important and environmentallyfriendly source of otherwise wasted energy.3,4 There has been already an important set of studies covering the mechanism involved during the conversion from thermal to electric energy. [5][6][7][8] Such studies have been the starting point to develop and optimize novel TE materials with the resourceful aid of uprising nanotechnologies. 9,10 In this review, we will first shortly introduce some important basic concepts and relations about thermoelectrics, as well as some of the current efforts to use nanotechnologies and nano-materials to improve performance and viability. Next, we will focus on identifying innovative devices, novel engineering approach...

Controllable Colloidal Synthesis of Tin(II) Chalcogenide Nanocrystals and Their Solution‐Processed Flexible Thermoelectric Thin Films

“…For example, the presence of nanoscale precipitates in In‐ and Cd‐codoped SnTe was reported to produce a great enhancement of the TE performance . Therefore, we believe this nanosizing approach, by applying nanoscale NCs to flexible films, could provide another means of nanostructuring for wearable and portable TE generators …”

Energy Harvesting Research: The Road from Single Source to Multisource

“…However, the development of high ZT thermoelectric materials provides space for a compromise on Δ T . This releases the potential of thermoelectric energy harvesters in, e.g., wearable electronics and the Internet of Things . There are also plenty of reviews focusing on the development of thermoelectric energy harvesters from the device aspect …”

Flexible Thermoelectric Materials and Generators: Challenges and Innovations

“…[69,70] In such organic/ inorganic hybrids, inorganic fillers such as inorganic TE particles [63,65,71] and carbon-based nanomaterials [72][73][74] can provide extra current pathways [75][76][77] and in turn induce energy-filtering effects in the flexible polymer matrix, while organic molecules can provide the desired flexibility for the inorganic host. [65,73] For inorganic FTE thin films, continuous flexibility can be realized through either depositing inorganic TE thin films on flexible substrates [78] using atomic deposition techniques, [79] or applying CNT scaffolds [80] or nanostructure tailoring [81] to develop free-standing inorganic FTE films.…”