A parylene MEMS flow sensing array

We have demonstrated the first parylene MEMS thermal sensor array capable of detecting small flows down to 0.5 /spl mu/l/min. The device is fabricated using low-temperature parylene/platinum technology and consists of metallic sensors suspended on a membrane over a bulk micromachined silicon channel. For the first time, insightful results from three different methods of flow sensing using a single device are studied and compared. Multi-mode testing using hot film, calorimetric, and time-of-flight techniques at low overheat ratios has been performed. Thus, this device is biocompatible in both construction and operation.