Micro thermoelectric cooler: Planar multistage

A suspended, planar multistage micro thermoelectric (TE) cooler is designed using thermal network model to cool MEMS devices. Though the planar (two-dimensional) design is compatible with MEMS fabrication, its cooling performance is reduced compared to that of a pyramid (three-dimensional) design, due to a mechanically indispensable thin dielectric substrate (SiO2) and technical limit on TE film thickness. We optimize the planar, six-stage TE cooler for maximum cooling, and predict ΔTmax = 51 K with power consumption of 68 mW using undoped, patterned 4–10 μm thick co-evaporated Bi2Te3 and Sb2Te3 films. Improvement steps of the planar design for achieving cooling performance of the ideal pyramid design are discussed. The predicted performance of a fabricated prototype is compared with experimental results with good agreements.