This proposal is submitted for research on using MEMS technology to make unique, highly reliable, miniaturized capillary pumped coolers in the application of Thermal Control for Instruments (subtopic: E1.07). The proposed miniaturized thermal-cooler can be fabricated on Si wafer or directly on the back of the IC circuits. The proposed micro-cooler potentially has high mechanical reliability. The proposed micro-cooler has its own coolant supply and needs no extra coolant reservoir and supply.