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Two in One: Light as a Tool for 3D Printing and Erasing at the Microscale
Author(s) -
Batchelor Rhian,
Messer Tobias,
Hippler Marc,
Wegener Martin,
BarnerKowollik Christopher,
Blasco Eva
Publication year - 2019
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201904085
Subject(s) - photoresist , materials science , scanning electron microscope , resist , laser , photopolymer , lithography , photolithography , photoinitiator , optoelectronics , optics , nanotechnology , polymer , polymerization , composite material , physics , monomer , layer (electronics)
The ability to selectively remove sections from 3D‐printed structures with high resolution remains a current challenge in 3D laser lithography. A novel photoresist is introduced to enable the additive fabrication of 3D microstructures at one wavelength and subsequent spatially controlled cleavage of the printed resist at another wavelength. The photoresist is composed of a difunctional acrylate cross‐linker containing a photolabile o ‐nitrobenzyl ether moiety. 3D microstructures are written by photoinduced radical polymerization of acrylates using Ivocerin as photoinitiator upon exposure to 900 nm laser light. Subsequent scanning using a laser at 700 nm wavelength allows for the selective removal of the resist by photocleaving the o ‐nitrobenzyl group. Both steps rely on two‐photon absorption. The fabricated and erased features are imaged using scanning electron microscopy (SEM) and laser scanning microscopy (LSM). In addition, a single wire bond is successfully eliminated from an array, proving the possibility of complete or partial removal of structures on demand.