Fabrication of monolithic flow sensor on tube structure

Si-MEMS flow sensors require a bonding process involving a complicated electrical wiring connection because they are generally mounted in a tube using a hybrid method. To overcome these problems, we propose here a monolithic type of flow sensor structure on polymer film, in which the thermal sensor is formed on the thin film, and the electrical wiring is connected to the outside directly. We also developed a fabrication process for producing it by using photolithography on a cylinder surface, and a heat shrinkable tube. Finally, we confirmed that the sensor was able to achieve a response time of less than 116 ms, which is comparable to commercially available mass flow controllers.