Fabrication of micro-mechanical planar cantilever beam-mass structures on quartz substrates using an ECDM process

Abstract

Electrochemical discharge machining (ECDM) processes have been used to realize miniature structures such as micro-channels and micro-holes on non-conductive materials such as quartz and Pyrex for a variety of applications. However, for realizing mechanical/physical sensors, actuators, energy harvesters, and resonators on glass substrates, free-standing devices with movable components such as beam-mass structures and cantilevers are required. There has been a negligible focus on developing miniature glass-based devices with movable components primarily due to the non-linear material removal rate (MRR) of the ECDM processes, requiring continuous measurement, tracking, and maintaining the working gap in the range of a few micrometers during micromachining. A couple of techniques were proposed to address maintaining a constant working gap, however, using costly equipment with complex feedback mechanisms. We report a two-stage experimental approach – without using feedback mechanisms and additional equipment – to realize micro-mechanical planar cantilever beam-mass structures on thick quartz substrates in the present work. In the first stage, the process parameters such as applied voltage, tool travel rate (TTR), and initial working gap ( Wg) are optimized for fabricating broader and deeper micro-channels using needle-shaped tools. In the second stage, using the optimized parameters, an array of micro-channels is fabricated. The cumulative depth, corresponding depth, and the width of each layer of the channels are measured, and this data is utilized for fabricating planar beam-mass structures on quartz substrates. We envisage that the experimental results of the present study would be beneficial for ECDM researchers to fabricate glass-based miniature devices with movable components without using complex tools and equipment.

Non-contact micromachining by a dynamic feed rate controlled electrochemical discharge machining process

“…13,14 At higher feed rates in this method, it is hard to discern between ECDM and physical machining, so the tool material must be suited to withstand contact with the workpiece. 15 Linear feed control was also reported to improve the contact issues at a deeper hole by reducing the feed rate through the machining process. 6 Another method, termed adaptive feed, involves withdrawing the tool by a fixed distance when the tool-workpiece contact is detected by a load cell or switch.…”

Micro-channel fabrication on GFRP composite through electrochemical spark machining method and optimization of process parameters

“…An auxiliary electrode is used as an anode whose surface area is larger than the tool electrode. 45 The tool is made as cathode 47 and connected to the negative terminal of the power supply. When the potential difference is applied across the tool and workpiece, the electrolysis process is initiated, due to which hydrogen bubbles formed near cathode (Figure 1(i)(a)), whereas at the anode, oxygen bubbles are generated.…”

Investigation through novel tool-electrode feeding approach on electrochemical discharge machining of glass

“…Besides making holes and channels, researchers have also used electrochemical discharge for making micro patterns on electrically non-conducting materials. Sambathkumar and Arunagirinathan 28 fabricated a cantilever beam structure on quartz material by applying the layer by layer machining process using needle shape tool-electrode. Harugade et al 29 used ECDM to remove delaminated fibers from reinforced composite material.…”