Smart materials and novel accessory techniques for microfabrication with two-photon lithography

Over the last forty years the idea to build robots the size of human cell has moved from a fantasy to real scientific research. Micro-electromechanical systems are overwhelmingly applied in automotive, consumer electronics and medicine. State-of-the-art technological developments enable 3D-printing with submicrometric precision. In particular 2-photon lithography offers extraordinary freedom to design microstructures with complex geometry and are furthermore easily customizable. The use of this technique is restricted due to the limited number of available materials. On top of that, it is difficult to integrate printed structures in other technologies. This is essential as microrobots are usually part of a larger electrical system.

In his thesis, Frank den Hoed offers several solutions to address the restrictions in the field. For instance, it describes a new method to transfer 3D-structures the size of a couple of micron from the flat glass slides in the printer towards a new arbitrary target. The placement is performed with micrometric precision. The thesis further contains research in smart materials for the 2-photon 3D-printer. By using such a smart material as a resin, it became possible to chemically alter the microstructure after printing, making it more water affinitive or repellant. Another smart material could reversible contract triggered by light irradiation. This allowed for controlled movement of the 3D-microstructure making it a functioning actuator. These results bring 3D-printing on microscale closer to commercial application.

Dissertation: https://hdl.handle.net/11370/4f2a0ec9-f8fb-4cae-8d44-a4ce0779c826