A High Power Density Micro-Thermoelectric Generator Fabricated by an Integrated Bottom-Up Approach

In this paper, we report a high power density cross-plane micro-thermoelectric generator (TEG) fabricated by integrating pulsed electroplating with micro-fabrication processes. The TEG consists of a total of 127 pairs of n-type Bi
₂
Te
₃
and p-type Sb
₂
Te
₃
thermoelectric pillars embedded in a SU-8 matrix in order to enhance the overall mechanical strength of the device. Both bottom and top electrical connections are formed by electroplating, which is advantageous because of facile and low cost fabrication and low parasitic electrical resistances. The device demonstrates a maximum power of 2990 μW at a temperature difference of 52.5 K, corresponding to a power density as high as 9.2 mW · cm
^-2
. The power density of our device is more than two times the highest value reported for the electroplated micro-TEGs in the literature, which can be attributed to the low internal resistance and high packing density of thermoelectric pillars.