S.C. Gauci, P. Somers, M. Aljuaid, M. Wegener, C. Barner-Kowollik, and H.A. Houck

Adv. Funct. Mater. 35, 2414713 (2025)

Abstract:

Classical photoresists utilized in direct laser writing (DLW) rely on photoinitiators and radical polymerization mechanisms to induce the cross-linking process. Herein, a simple initiator-free photoresist is introduced that enables the rapid fabrication of intrinsically thermally degradable 3D microstructures via DLW. The reported photoresist exploits the [2 + 2] photo-dimerization reaction of a multifunctional monosubstituted thiomaleimide compound while harvesting on-demand microstructure degradation through the intrinsic thermally reversible nature of the photocrosslinks. The photoresist exceeds attainable DLW printing speeds for non-chain growth resins, readily attaining 1500 µm s⁻¹ and up to 5000 µm s⁻¹, making it a promising system to compete with traditional photo-initiator containing resists while introducing on-demand post-printing degradability.