Showing papers by "Gwo-Bin Lee published in 1997"
26 Jan 1997
TL;DR: In this paper, a new microfabrication technology that enables the integration of MEMS devices on a flexible polyimide skin has been developed, which consists of many individual Si islands (necessary for silicon MEMS/electronics devices) that are connected together by a thin/thick polyimides film (typically 1-100 /spl mu/m thick).
Abstract: A new microfabrication technology that enables the integration of MEMS devices on a flexible polyimide skin has been developed. Mechanically, the flexible skin consists of many individual Si islands (necessary for silicon MEMS/electronics devices) that are connected together by a thin/thick polyimide film (typically 1-100 /spl mu/m thick). To create the islands, Si diaphragms are first formed with a desirable thickness (10-500 /spl mu/m) by Si wet etching and then patterned from the back side by reactive ion etching (RIE). As a first application, flexible shear-stress sensor skins for aerodynamics study have been fabricated. The finished skin is 3 cm long and 1 cm wide, and it consists of about 100 sensors. The skin polyimide is 17 /spl mu/m thick and the silicon islands are 75 /spl mu/m thick. These skins have been successfully taped on a semi-cylindrical (1.3 cm diameter) delta wing leading edge to perform real-time 2-D shear stress profiling.
115 citations
06 Jan 1997
32 citations
01 Feb 1997
TL;DR: In this article, the authors used microactuators with a thickness comparable to that of the boundary layer in order to alter the separation process and thus achieved control of the global motion by minute perturbations.
Abstract: Micro-ElectroMechanical-Systems (MEMS) have emerged as a major enabling technology across the engineering disciplines. In this study, the possibility of applying MEMS to the aerodynamic field was explored. We have demonstrated that microtransducers can be used to control the motion of a delta wing in a wind tunnel and can even maneuver a scaled aircraft in flight tests. The main advantage of using micro actuators to replace the traditional control surface is the significant reduction of radar cross-sections. At a high angle of attack, a large portion of the suction loading on a delta wing is contributed by the leading edge separation vortices which originate from thin boundary layers at the leading edge. We used microactuators with a thickness comparable to that of the boundary layer in order to alter the separation process and thus achieved control of the global motion by minute perturbations.
9 citations