Initiator-free photo-crosslinkable cellulose-based resists for fabricating submicron patterns via direct laser writing

TL;DR

This paper introduces bio-based cellulose derivatives that can be directly patterned using laser writing without photoinitiators, enabling submicron fabrication through two-photon absorption and UV crosslinking.

Contribution

It presents novel cellulose derivatives functionalized for initiator-free photo-crosslinking and laser structuring, advancing sustainable bio-based resist materials.

Findings

Successful synthesis of cellulose derivatives with thiol and olefinic groups

Effective structuring via two-photon absorption without photoinitiators

UV crosslinking achieved without additional initiators

Abstract

Novel bifunctional cellulose diacetate derivatives were synthesized in order to achieve bio-based photoresists, which can be structured by two-photon absorption via direct laser writing (DLW) without the need to use a photoinitiator. Therefore, cellulose diacetate is functionalized with thiol moieties and olefinic or methacrylic side groups enabling thiol-conjugated crosslinking. These cellulose derivatives are also photo-crosslinkable via UV irradiation ($\lambda$ = 254 nm and 365 nm) without using an initiator.