Flexible micromachine-based shear-stress sensor array and its application to separation-point detection

Abstract

A new microfabrication technique has evolved and has been applied to the development of a flexible shear-stress sensor array. The flexible sensor array is composed of many silicon islands that are interconnected by two layers of polyimide film. The silicon islands are formed by RIE etching and contain individual thermal shear-stress sensors. Each sensor on the flexible sensor array has been proven to behave the same as those on a rigid substrate. There are more than 100 sensors distributed inside a 1 cm×3 cm area. The flexible sensor array has a thickness of 80 μm and can be easily attached on a highly curved surface to detect shear-stress distribution. Applications of the flexible sensor array to flow separation-point detection have been demonstrated in this task, including flow over a circular cylinder and instantaneous separation line detection on the rounded leading edges of a delta wing.