Micro thermoelectric modules and their application to wristwatches as an energy source

Microthermoelectric (TE) coolers are currently used in high power electronic devices such as laser diodes to stabilize temperature. With the aim of miniaturizing this technology, we have developed a fabrication technique to create micro-TE modules with a cross-section element size of about 100 /spl mu/m/spl times/100 /spl mu/m and a height of several hundred mm. We have previously reported the cooling properties of a module fabricated by this technique. With the recent advances in micro-electric technology, which has decreased the energy consumption in an electric wristwatch to about 1 /spl mu/W, there has been increased discussion about utilizing these micro-TE modules to generate energy of several /spl mu/W to power a wristwatch. In response, we have developed a micro-TE module with an overall size of 2 /spl times/ 2 /spl times/ 1.3 mm consisting of more than 50 pairs of elements, and have succeeded in making and marketing a TE powered wristwatch. This paper presents the fabrication and the properties of the micro-TE module, as well as the TE powered wristwatch.