Heterogeneous bonding between cyclo‐olefin polymer (COP) and glass‐like substrate by newly developed water vapor‐assisted plasma, Aqua Plasma Cleaner

To develop high‐performance and low‐cost microfluidic devices, heterogeneous bonding with cyclo‐olefin polymer (COP) and glass substrate was investigated by low‐pressure plasma using water vapor. COP and glass‐like substrate were bonded at room temperature under its own weight, and the bonding strength reached the breaking point of base material strength. Water contact angle of the COP and glass surface after water vapor plasma was less than 1° (superhydrophilic) and showed stable hydrophilicity even after 30 days. Water vapor plasma and COP surface were analyzed by optical emission spectroscopy (OES) and x‐ray photoelectron spectroscopy (XPS) to study the reaction of room temperature bonding.