Glass micro-structuring by electrochemical discharges

随着芯片实验室和微型器件制造需求的增加，玻璃在微型技术领域的意义越来越大。光学开关、电子电路的冷却元件和用于生物医学应用的微混合器是要求玻璃微加工的几个例子。对于这些应用，玻璃需要具有特定的性能。因此，需要能够加工具有特定表面特性的玻璃的技术。我们对电化学放电（ECD）应用于玻璃微加工（火花辅助化学雕刻; SACE）的研究使该技术达到一定程度的成熟度，从而在不久的将来实现微流控芯片通孔钻孔的商业化。但SACE（精度、可重复性、提高材料去除率）的优化工作仍需进行。过程控制算法仍然缺失。成功解决这些问题将使SACE进入需要非常高精度的微钻孔的应用，例如微喷嘴制造。为了进一步拓宽SACE的应用领域，必须更好地开发ECD的潜力。ECD不仅携带热量（用于促进局部玻璃蚀刻），还携带电子。因此，可以利用在这些放电附近发生的局部电化学反应。这个想法是利用我们在开发的路线，通过ECD纳米粒子的合成。合乎逻辑的下一步是联合收割机结合这两个领域的知识，以开发一种新的工艺，通过用金属纳米团簇掺杂玻璃来局部改变玻璃性质（例如，玻璃表面的颜色、纹理、机械强度）。通过ECD对玻璃进行局部改性将为SACE在微流体、生物医学或光学器件的微制造中开辟新的应用。

Glass gains significance in the micro technology field with the boost in the demand of lab-on-a-chip and micro devices fabrication. Optical switches, cooling elements for electronics circuits and micro-mixers for biomedical applications are few examples demanding glass micro-machining. For these applications, glass is required to have specific properties. Hence, the need for technologies able to machine glass, with specific surface properties, has become a necessity. Our study of the application of electrochemical discharges (ECD) to glass micro-machining (Spark Assisted Chemical Engraving; SACE) allowed reaching a degree of maturity of this technology bringing commercialisation in a very near future for vias drillings in micro-fluidic chips. But work on the optimisation of SACE (precision, repeatability, enhance material removal rate) is still needed. Process control algorithms are still missing. Addressing successfully these issues will allow SACE to enter applications requiring very high precision micro-drilling, such a micro-nozzle fabrication. To further open fields of applications to SACE, the potential of ECD have to be exploited better. ECD do not only carry heat (used to promote local glass etching), but electrons as well. It is therefore possible to take advantage of localised electrochemical reactions occurring in the vicinity of these discharges. This idea was exploited by us in developing a route for nanoparticle synthesis by ECD. The logical next step is to combine the knowledge of both fields in order to develop a new process to modify locally glass properties (e.g. color, texture, mechanical strength of the glass surface) by doping glass with metal nano-clusters. Local glass modification by ECD will open new applications for SACE for the micro-fabrication of micro-fluidic, bio-medical or optical devices.