title: Formulating an Ideal Protein Photoresist for Fabricating Dynamic Microstructures with High Aspect Ratios and Uniform Responsiveness.
abstract: The physical properties of aqueous-based stimuli-responsive photoresists are crucial in fabricating microstructures with high structural integrity and uniform responsiveness during two-photon lithography. Here, we quantitatively investigate how various components within bovine serum albumin (BSA) photoresists affect our ability to achieve BSA microstructures with consistent stimuli-responsive properties over areas exceeding 10(4) μm(2). We unveil a relationship between BSA concentration and dynamic viscosity, establishing a threshold viscosity to achieve robust BSA microstructures. We also demonstrate the addition of an inert polymer to the photoresist as viscosity enhancer. A set of systematically optimized processing parameters is derived for the construction of dynamic BSA microstructures. The optimized BSA photoresists and processing parameters enable us to extend the two-dimensional (2D) microstructures to three-dimensional (3D) ones, culminating in arrays of micropillars with aspect ratio > 10. Our findings foster the development of liquid stimuli-responsive photoresists to build multifunctional complex 3D geometries for applications such as bioimplantable devices or adaptive photonic systems.
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , 637371 Singapore.|Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR) , 2 Fusionopolis Way, Innovis, 08-03, 138634 Singapore.
authors.forename: Chee Leng
authors.initials: CL
authors.lastname: Lay
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , 637371 Singapore.
authors.forename: Yih Hong
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , 637371 Singapore.
authors.forename: Mian Rong
authors.initials: MR
authors.lastname: Lee
authors.affiliation: Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR) , 2 Fusionopolis Way, Innovis, 08-03, 138634 Singapore.
authors.forename: In Yee
authors.initials: IY
authors.lastname: Phang
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , 637371 Singapore.|Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR) , 2 Fusionopolis Way, Innovis, 08-03, 138634 Singapore.
authors.forename: Xing Yi
authors.initials: XY
authors.lastname: Ling
mesh_terms: D000818:Animals; D002417:Cattle; D055668:Photochemical Processes; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D014783:Viscosity
chemical_list: D012710:Serum Albumin, Bovine
keywords: bovine serum albumin; free-standing microstructures; high aspect ratio; two-photon lithography; uniform stimuli responsiveness