Conversion of a 3D printer for versatile automation of dip coating processes

The necessity of increased sample throughput has led to increased usage of robotic systems and automation of sample preparation processes. Many devices, especially for dip coating applications, are mechanically simple but, nevertheless, require large financial investments. Here, a low-cost alternative to commercial dip coaters based on a readily available 3D printer is presented and resulting films are compared to those obtained from an exemplary commercial device. The 3D printer-based device is able to automate the dip coating process by performing complex multi-layer procedures using up to six different dipping solutions for a batch of up to six samples, potentially saving the many person-hours otherwise spent changing solutions and/or samples of more simple but also more expensive commercial systems. Coatings can be defined in terms of the sample used, dipping height, acceleration, speed, and the solution to be dipped into. The film quality from the home-built is compared to a representative commercial system with exemplary dip coating processes based on the deposition of thin films of polymethylmethacrylate (PMMA) from an ethyl acetate solution. The thin film quality is investigated by spectroscopic ellipsometry and profilometry. The film thicknesses achieved by both systems were comparable, and the home-built system performs similarly and, in some instances, better than the commercial one in terms of uniformity and roughness. Due to the similar performance, the higher level of automation, and significantly lower cost, the presented conversion of a 3D printer is a viable alternative to acquiring a commercial dip coating device.