Researchers at the Indian Institute of Technology Bombay have uncovered the mechanism behind a fast-advancing micro-drilling technique that sharply improves precision in brittle materials such as glass, ceramics, composites and advanced industrial components.

The findings could accelerate innovation in sectors ranging from consumer electronics to medical devices, where ultra-fine, crack-free holes are critical.

Demand for high-strength brittle materials has surged — from smartphone screens to high-precision medical tools — but drilling micro-scale holes, often as thin as a human hair, remains a major manufacturing challenge. Traditional processes struggle with debris buildup, restricted electrolyte flow and crack formation.

Ultrasonic-Assisted Electrochemical Discharge Machining (UA-ECDM), which merges controlled electrical sparks with rapid ultrasonic vibrations, has recently emerged as a promising solution. While experiments showed that the method enabled deeper, cleaner and more precise drilling, the physics behind its superior performance had largely remained unclear.

A new study by Anurag Shanu and Prof. Pradeep Dixit at IIT Bombay closes that gap.
“Earlier studies focused mainly on experimental results but did not explain the mechanism behind the performance improvement,” said Prof. Dixit, Associate Professor in the Department of Mechanical Engineering. “By analysing electrolyte flow and debris dynamics, we explained the fundamental mechanism and the role of vibration amplitude in boosting debris removal efficiency.”

Electrochemical discharge machining works by producing tiny, lightning-like discharges in an electrolyte to vaporise micro-portions of material. As a hole deepens, however, debris builds up and blocks the circulation of fresh electrolyte, slowing the process and reducing precision.

The IIT Bombay research shows that ultrasonic vibrations act as a powerful debris-clearing driver, improving flow, stabilising discharge formation and maintaining consistent machining performance.

The study also highlights how fine-tuning vibration amplitude can further enhance precision, making UA-ECDM especially valuable for drilling blind and through-holes, micro-channels and other deep micro-features in nonconductive materials such as soda-lime glass, borosilicate glass, fused silica, alumina and polymer-based composites.

Beyond improved accuracy, the method enables simultaneous drilling of deeper, multiple holes while reducing tool wear — a major manufacturing advantage. However, the researchers note that even with enhanced capabilities, the minimum achievable hole size will continue to depend on the limitations of current tool-making processes, which rely on wire EDM and cannot yet produce ultra-fine tool tips.

The findings, experts say, strengthen UA-ECDM’s potential as a next-generation micro-machining method for industries that rely on high-precision brittle materials.