Visible Light Degradable 3D Microstructures in Aqueous Environments.

The additive manufacturing technique direct laser writing (DLW), also known as two-photon laser lithography, is becoming increasingly established as a technique capable of fabricating functional three-dimensional microstructures. Recently, there has been an increasing effort to impart microstructures fabricated using DLW with advanced functionalities by introducing responsive chemical entities into the underpinning photoresists. Herein, we introduce a novel photoresist based on the photochemistry of the bimane group that can be degraded upon exposure to very mild conditions, requiring only water and visible light (λ = 415-435 nm) irradiation. The degradation of the microstructures was tracked and quantified using AFM measurements of their height. The influence of the writing parameters as well as the degradation conditions was investigated, unambiguously evidencing effective visible light degradation in aqueous environments. Finally, we demonstrate the utility of the photodegradable resist system by incorporating it into multi-material three-dimensional microstructures, serving as a model for future applications. This article is protected by copyright. All rights reserved.