Mechanical Engineering Commons^™

Enhanced Fabrication Of Microdroplet Generator Nozzle Arrays: Optimizing Koh Etching For Microfluidic Applications, Hongyu Bai

McKelvey School of Engineering Theses & Dissertations

Ultrasonic microdroplet generators are useful devices with broad applications ranging from aerosolized drug delivery to three-dimensional (3D) printing-based additive manufacturing. One such technology comprises a microfabricated array of nozzles with droplet production driven by a piezoelectric transducer. The present study focuses on refining a critical fabrication step, anisotropic wet etching of pyramidal nozzles using a basic potassium hydroxide (KOH) solution. Given the integral role of nozzle geometry in device operation, high-precision techniques including Reactive Ion Etching (RIE), Deep Reactive Ion Etching (DRIE), and KOH wet etching were employed. A tapering geometry is preferred for acoustic wave focusing and efficient droplet …