目前用于制造小深孔的电解加工技术有异形管电解加工（STEM）、毛细管钻孔（CD）和气流钻孔（ESD）。这些工艺使用强酸电解液，产生无应力、无损伤的高长径比（高达300:1）微孔。实现了酸液流量和压力的复杂闭环控制，以及其他加工参数的精确控制。使用CD和ESD时，形成钻面的玻璃管的钻孔破裂或碎屑是导致废料的常见问题。 开发了一种监测钻井过程中钻井电流和高频发射的方法。该系统可以成功地检测到95%以上的钻头破损，且错误报警最少。

THE ECM TECHNIQUES CURRENTLY USED FOR PRODUCING SMALL DEEP HOLES ARE SHAPED TUBE ELECTROLYTIC MACHINING (STEM), CAPILLARY DRILLING (CD), AND ELECTROSTREAM DRILLING (ESD). THESE PROCESSES USE A STRONG ACID ELECTROLYTE AND CREATE STRESS FREE, METALLURGICALLY UNDAMAGED MICROHOLES OF HIGH LENGTH TO DIAMETER RATIO (UP TO 300:1). COMPLEX CLOSED LOOP CONTROL OF ACID FLOW AND PRESSURE, CONJOINT WITH PRECISE CONTROL OF OTHER MACHINING PARAMETERS, HAS BEEN ACHIEVED. WITH CD AND ESD, DRILL BREAKAGE OR CHIPPING OF THE GLASS TUBES WHICH FORM THE DRILL FACE IS A COMMON PROBLEM CAUSING SCRAP. A MEANS OF MONITORING DRILLING CURRENT AND HIGH FREQUENCY EMISSION DURING THE PROCESS HAS BEEN DEVELOPED. THIS SYSTEM CAN SUCCESSFULLY DETECT MORE THAN 95% OF DRILL BREAKAGE WITH A MINIMUM OF FALSE ALARMS.