Multi-material 3D microstructures with photochemically adaptive mechanical properties

Abstract

The popularity of direct laser writing as a technique capable of producing truly three-dimensional structures at the microscale is remarkable. However, examples of resists imparting adaptable functionality onto microstructures are still scarce. Herein, we describe multi-material boxing ring microstructures with locally visible light-responsive mechanical properties from an anthracene dimer-based photoresist. Utilizing microstructures created from this material is a powerful avenue for changing the mechanics of a well-defined microenvironment. A higher laser exposure per unit of time cleaves more anthracene dimer during the writing process which is then available for further photochemistry. We find that not only the viscoelastic properties but also the photo-responsiveness of these microstructures is drastically impacted by the parameters they were written with. Realizing that the laser irradiation during the direct laser writing process can be used to trigger secondary chemistry opens the door to an entirely new approach to designing photoresists.