Copper Plated Microchannel Heat Exchanger for MEMS Application

Abstract

Demand for increased density circuit architecture, micro- and nano-scale devices, and the overall down-scaling of system components has driven research into understanding transport phenomena at reduced scales. One method to enhance transport processes is the utilization of mini-, micro-, or nano-channels which drive uniform temperature and velocity profiles throughout the system. This work specifically examines a unique heat exchanger. The exchanger is developed as a closed system, with 300μm width channels, fabricated entirely with copper. The heat exchanger has been designed for widespread use in varied environments. Further, the exchanger is working fluid non-specific, allowing for different fluids to be specified for various temperature ranges. The system design can be used equally well as a standalone heat exchanger or coupled with another device to provide a thermal energy storage system. Fabricating the heat exchanger with copper for the substrate as well as the channels themselves allows the exchanger to maintain a high thermal conductivity which aides in the fluid energy transference. The exchanger was fabricated to be a closed system removing any excess equipment such as pumps. In testing, the exchanger showed thermal absorption of 2.2kW/m2 given input of 2.63kW/m2 and working fluid amounts of 37μL. The general design and use of copper in the exchanger allowed maximum absorption of 84% of the input with operation below the boiling point of the working fluid.

Investigations of a new free piston expander engine cycle

“…In this work, the use of capillary channels was the primary means for fluid transport. Relatedly, unique materials and fabrication processes that included electroplated porous nickel [9] or copper [10] have been under development. The option of thermal energy storage for a system of this type has also been investigated using paraffin wax as the storage media [11].…”