Modeling of Micromachined Thermopiles Powered from the Human Body for Energy Harvesting in Wearable Devices

• Main Authors: Vladimir Leonov, Ziyang Wang, Paolo Fiorini, Chris Van Hoof
• Format: Article
• Language: English
• Published: IFSA Publishing, S.L. 2009-04-01
• Series: Sensors & Transducers
• Subjects: Thermoelectric generator; Energy harvesting; MEMS; Thermopile
• Online Access: http://www.sensorsportal.com/HTML/DIGEST/april_09/P_410.pdf

The design of thermoelectric MEMS converters (power generators) suited for self-powered wearable devices is proposed and analyzed. Micromachined thermopiles are designed on top of a silicon rim and their performances are modeled for two thermoelectric materials, BiTe and polycrystalline SiGe. The advantage of the proposed design in respect to existing ones is a large output voltage combined with a relatively large generated power. The design is developed for a watch size generator and takes into account limitations of contact lithography in terms of aspect ratio and minimum feature size. Within these limitations, the output voltage is close to 1V while the output power is in excess of 1 mW for poly-SiGe based generators and close to 10 mW for BiTe based ones.