Phase change and cooling characteristics of microjets measured using microcantilever heaters

✍ Scribed by Jungchul Lee; Hanif Hunter; Ari Glezer; William P. King

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 1008 KB
• Volume: 147
• Category: Article
• ISSN: 0924-4247
• DOI: 10.1016/j.sna.2008.03.022

✦ Synopsis

This paper reports novel microcantilever metrology tools to investigate free microjets emanating from a micromachined nozzle of diameter 10 m. Microcantilevers with an integrated resistive heaterthermometer were used to study microjet cooling and phase change characteristics. While the microcantilever heater was aligned to and impinged upon by hydrocarbon microjets, the heater temperature was modulated by a constant voltage source. Successive heating and cooling cycles captured the microjet phase change hysteresis properties. When the microcantilever heater temperature was controlled, it was possible to construct a full boiling curve. Measurements were made on microjets of butane, hexane, and octane. The convective heat fluxes accompanied by microjet impingement boiling were 2.9-7.6 kW/cm 2 for heater temperatures of 25-350 • C. Overall, the techniques reported herein show promise for characterizing microscale jet flows.