Thermoelectric conversion is used in waste heat recovery, energy harvesting and solid-state cooling. This solid-state energy conversion technology is environmentally friendly, but the production of efficient, low-cost and flexible thermoelectric materials is extremely difficult due to a number of materials and manufacturing challenges.
Energy harvesting applications to power sensors, biomedical devices and waste heat recovery along contoured surfaces, are applications where using flexible thermoelectric devices is extremely attractive. Wearable electronics, an area currently experiencing exponential growth would also benefit greatly from the availability of these devices.
An innovative screen-printing process was recently used in a study at Boise State University led by Professor Yanliang Zhang. The process was used to manufacture low cost, high performance, flexible thermoelectric devices and films and allows nanocrystals to be converted into flexible thermoelectric devices directly.
The printed thermoelectric materials achieve unprecedented performances. The key factors allowing this are the optimization of the nano ink and screen-printing process, as well as the exact control of the starting nanocrystals’ shape.
A preliminary cost analysis indicates that the screen-printed films can be used to produce thermoelectric devices at 2-3 cents per watt. This is an order of magnitude lower than similar existing state of the art commercial devices. This cost reduction would make thermoelectrics very competitive compared to other energy conversion technology devices and open up largely underexplored markets for waste heat recovery.
This additive printing method will certainly benefit thermoelectrics. It could however also be used in a disruptive manufacturing approach for other energy conversion technologies, electronic devices, and storage technologies. This would result in a completely new range of flexible, ultralow cost devices.
Zhang envisions enabling major technology breakthroughs by combining advanced energy technology with additive manufacturing. A major federal funding agency has recognized the potential of this concept and Zhang has recently received an infrastructure award from the U.S. Department of Energy. The award will be used to establish state of the art additive manufacturing facilities at Boise State by investing in advanced additive printing equipment.
These new facilities will allow students to perform innovative research on additive manufacturing and their applications on storage systems, printing sensors, energy conversion and flexible electronics.
Full research has been published in the journal Scientific Reports.