Abstract
This work presents an energy efficient technique for fabricating flexible thermoelectric generators while using printable ink. We have fabricated thermoelectric composite thick films using two different mesh sizes of n-type bismuth particles, various binder to thermoelectric material weight ratios, and two different pressures, 200 MPa and 300 MPa, in order to optimize the thermoelectric properties of the composite films. The use of chitosan dissolved in dimethylsulfoxide with less than 0.2 wt. % of chitosan, the first time chitosan has been used in this process, was sufficient for fabricating TE inks and composite films. Low temperature curing processes, along with uniaxial pressure, were used to evaporate the solvent from the drop-casted inks. This combination reduced the temperature needed compared to traditional curing processes while simultaneously increasing the packing density of the film by removing the pores and voids in the chitosan-bismuth composite film. Microstructural analysis of the composite films reveals low amounts of voids and pores when pressed at sufficiently high pressures. The highest performing composite film was obtained with the weight ratio of 1:2000 binder to bismuth, 100-mesh particle size, and 300 MPa of pressure. The best performing bismuth chitosan composite film that was pressed at 300 MPa had a power factor of 4009 ± 391 μW/m K2 with high electrical conductivity of 7337 ± 522 S/cm. The measured thermal conductivity of this same sample was 4.4 ± 0.8 W/m K and the corresponding figure of merit was 0.27 at room temperature.
Highlights
As the rate of energy consumption continues its rapid growth, energy conversion processes are facing a great challenge to meet the demand
This study reports an experimental study undertaken to understand the effect of TE particle size on the electrical conductivity of composite TE films
Prior to preparing the inks, scanning electron microscope (SEM) was performed on the purchased bismuth particles
Summary
As the rate of energy consumption continues its rapid growth, energy conversion processes are facing a great challenge to meet the demand. When considering that the majority of energy is wasted in the form of heat during device and machine operations (e.g., automobile engines, power transistors, light bulbs, industrial processes, etc.), energy harvesting devices, such as a thermoelectric generator (TEG), can be used to convert the waste heat into electricity [1,2,3]. The long lifespan of TEGs, coupled with fewer replacement requirements than other devices, such as solar cells, make it an attractive technology for energy harvesting. The conventional manufacturing of TEGs dices an ingot of bulk material and, subsequently, assembles and integrates the diced piece. The conventional pick-and-place methods for thermoelectric device manufacturing are limited to low aspect-ratio elements and the associated micro-fabrication technology has a limited cost-effective scalability
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
