Fully printed origami thermoelectric generators for energy-harvesting

Abstract

Energy-harvesting from low-temperature environmental heat via thermoelectric generators (TEG) is a versatile and maintenance-free solution for large-scale waste heat recovery and supplying renewable energy to a growing number of devices in the Internet of Things (IoT) that require an independent wireless power supply. A prerequisite for market competitiveness, however, is the cost-effective and scalable manufacturing of these TEGs. Our approach is to print the devices using printable thermoelectric polymers and composite materials. We present a mass-producible potentially low-cost fully screen printed flexible origami TEG. Through a unique two-step folding technique, we produce a mechanically stable 3D cuboidal device from a 2D layout printed on a thin flexible substrate using thermoelectric inks based on PEDOT nanowires and a TiS2:Hexylamine-complex material. We realize a device architecture with a high thermocouple density of 190 per cm² by using the thin substrate as electrical insulation between the thermoelectric elements resulting in a high-power output of 47.8 µWcm−² from a 30 K temperature difference. The device properties are adjustable via the print layout, specifically, the thermal impedance of the TEGs can be tuned over several orders of magnitudes allowing thermal impedance matching to any given heat source. We demonstrate a wireless energy-harvesting application by powering an autonomous weather sensor comprising a Bluetooth module and a power management system.

Fabrication of Millimeter Thick Polymer‐Based Thermoelectric Devices by Solvent‐Free Printing

“…To date, fabricating millimeter order thick polymer‐based TEDs requires a vertical‐type device structure composed of multi‐stacked standing polymer‐based thin films. [ 6,27,28 ] This approach facilitates high power output; however, it diminishes the important characteristics of TEDs based on CNT/polymer composites, such as flexibility and ease of large‐area‐device fabrication. [ 6 ] The SFP enables thick, flexible polymer‐based TEDs to be fabrication in a facile manner.…”

“…To avoid this issue, vertical type devices consisting of standing thin CNT/polymer films have been investigated. [ 27,28 ] However, this approach diminishes the important characteristics of TEDs based on CNT/polymer composites, such as flexibility and ease of fabrication of large‐area devices. Thus, the resolution of this issue is still important.…”

Realizing High Thermoelectric Performance of Bi-Sb-Te-Based Printed Films through Grain Interface Modification by an In Situ-Grown β-Cu2-δSe Phase

“…Temperature-dependent S of the printed films was measured using a custom-built setup with an experimental measurement error of ∼10% in the temperature range from 300 to 373 K. The custom-built setup has been described in detail in the previous report. 33 The measurement errors related to σ and κ are 6 and 10%, respectively. Temperature-dependent bulk thermal conductivities (κ) of 10 mm discs made of (1 − x)BST−(x)IB inks by cold pressing at 50 MPa pressure followed by sintering at 703 K in vacuum for 10 min were determined using a Netzsch LFA-427.…”

Energy Harvesting Technology by Converting Waste Heat Energy from Automobiles

“…Their design philosophy will encourage the development of high-performance TEDs for flexible and wearable applications [7]. Andres Georg Rösch and his colleagues showed a wireless power harvested technology by powering an automated weather sensor that included a Bluetooth module and a voltage regulation system [8]. DingLuo and his colleagues developed a unique fluidthermal-electric multiphysics numerical model to forecast the performance of a thermoelectric generator system used in car waste heat recovery.…”

“…The plates have an auxiliary unbending character, a level mounting surface, and a dielectric layer to stop electric short circuits [7]. [8] Energy Harvesting Technology by Converting Waste Heat Energy from Automobiles II. DESIGN OF WASTE HEAT ENERGY HARVESTER Fig.…”