Ultrafast Laser-Enabled 3D Glass Microchannel Reactors

Microchannel reactors are among the most important tools used for high-performance continuous-flow synthesis. However, most microchannel reactors manufactured with conventional micromachining techniques are limited to two-dimensional (2D) planar geometries, which pose significant challenges for the custom production of three-dimensional (3D) architectures that offer superior microchemical performance. Using unique nonlinear optical effects of ultrafast lasers, hollow microchannel structures with 3D configurations can be flexibly created within transparent glass materials through either direct removal or subsequent chemical etching methods. This review provides an overview of typical fabrication techniques for 3D glass microchannel reactors based on ultrafast laser microfabrication, as well as their state-of-the-art advancements, including large-scale and high-precision manufacture of all-glass microchannels and the facile integration of online monitoring modules. Moreover, the applications of these fabricated microchannel reactors for various continuous-flow microchemical reactions are introduced. Ultrafast laser-enabled 3D glass microchannel reactors hold great potential for developing innovative and industrial-scale continuous-flow manufacturing processes in chemical engineering and pharmaceutical production.