Low temperature bonding of poly(methylmethacrylate) electrophoresis microchips by in situ polymerisation

A novel method for bonding poly(methyl methacrylate) (PMMA) electrophoresis microchips at the temperature below the glass transition temperature of PMMA based on in situ polymerization has been demonstrated. Methyl methacrylate (MMA) containing initiators was allowed to prepolymerize in an 85 °C water bath for 8 min and 15 min to produce a bonding solution and a dense molding solution, respectively. The channel plate of the PMMA microchip was fabricated by the UV-initiated polymerization of the molding solution between a nickel template and a PMMA plate at room temperature. Prior to bonding, the blank cover was coated with a thin layer of the bonding solution and was bonded to the channel plate at 95 °C for 20 min under the pressure of binder clips. The attractive performance of the PMMA chips bonded by the new approach has been demonstrated by separating and detecting dopamine, catechol, three cations, and three organic acids in connection with end-column amperometric detection and contactless conductivity detection.