2 A Self-Adaptive Thermal Switch Array for Rapid Temperature Stabilization under Various Thermal Power Inputs
Xiaobao Geng, Department of Mechanical Engineering - Engineering Mechanics Advisor:Dr. Dennis D. Meng
A self-adaptive thermal switch array (TSA) based on actuation by low-melting-point alloy (LMA) droplets is reported to stabilize the temperature of a heat-generating MEMS device at a predetermined range (i.e., the optimal working temperature of the device) with neither control circuit nor electrical power consumption. Many microdevices, in form of microelectromechanical systems (MEMS), work best in certain temperature ranges, usually higher than room or ambient temperature, such as microbatteries, microfuel cells, chemical sensors, micro total analysis systems (TAS), and chip scale atomic clocks. There has been growing demand for more sophisticated temperature regulation schemes to stabilize the working temperature when the operational mode changes frequently or environmental temperature fluctuates dramatically (e.g., in outer space or desert areas). We propose a self-adaptive thermal switch array (TSA), which can be actuated by low melting point alloy (LMA) during its phase change. When the temperature is below this range, the TSA stays off and works as a thermal insulator. Therefore, the MEMS device can quickly heat itself up to its optimal working temperature during startup. Once this temperature is reached, TSA is automatically turned on to increase the thermal conductance, working as an effective thermal spreader. As a result, the MEMS device tends to stay at its optimal working temperature without complex thermal management components and the associated parasitic power loss. A prototype TSA was fabricated and characterized to prove the concept. The stabilization temperatures under various power inputs have been studied both experimentally and theoretically. Under the increment of power input from 3.8 W to 5.8 W, the temperature of the device increased only by 2.5C due to the stabilization effect of TSA.
2 A Self-Adaptive Thermal Switch Array for Rapid Temperature Stabilization under Various Thermal Power Inputs
Xiaobao Geng, Department of Mechanical Engineering - Engineering Mechanics Advisor:Dr. Dennis D. Meng
A self-adaptive thermal switch array (TSA) based on actuation by low-melting-point alloy (LMA) droplets is reported to stabilize the temperature of a heat-generating MEMS device at a predetermined range (i.e., the optimal working temperature of the device) with neither control circuit nor electrical power consumption. Many microdevices, in form of microelectromechanical systems (MEMS), work best in certain temperature ranges, usually higher than room or ambient temperature, such as microbatteries, microfuel cells, chemical sensors, micro total analysis systems (TAS), and chip scale atomic clocks. There has been growing demand for more sophisticated temperature regulation schemes to stabilize the working temperature when the operational mode changes frequently or environmental temperature fluctuates dramatically (e.g., in outer space or desert areas). We propose a self-adaptive thermal switch array (TSA), which can be actuated by low melting point alloy (LMA) during its phase change. When the temperature is below this range, the TSA stays off and works as a thermal insulator. Therefore, the MEMS device can quickly heat itself up to its optimal working temperature during startup. Once this temperature is reached, TSA is automatically turned on to increase the thermal conductance, working as an effective thermal spreader. As a result, the MEMS device tends to stay at its optimal working temperature without complex thermal management components and the associated parasitic power loss. A prototype TSA was fabricated and characterized to prove the concept. The stabilization temperatures under various power inputs have been studied both experimentally and theoretically. Under the increment of power input from 3.8 W to 5.8 W, the temperature of the device increased only by 2.5C due to the stabilization effect of TSA.