A Simple and Fast Compression-Based Method to Fabricate Responsive Gold-pNIPAM Hybrid Materials: From Thin Films to Anisotropic Microgels

In recent years, hydrogel-based soft materials with hybrid properties have found widespread use in various technological fields, including tissue engineering, soft actuators, and flexible electronics. The proper implementation of these smart multifunctional materials into real-world applications requires the development of simple, cost-effective, and large-scale fabrication methods. Herein, a simple compression- and colloid-based method is presented to fabricate responsive Au-poly(N-isopropylacrylamide) (pNIPAM) hybrid films using photopolymerizable resin containing Au-pNIPAM core-shell microgels as building blocks. Uniform Au-pNIPAM hybrid films of 25 x 25 mm with adjustable thickness in the micron-size range (2.3-1.2 & mu;m) w ere successfully fabricated on glass substrates and flexible commercial acetate sheets. The resulting flexible Au-pNIPAM films exhibit robust optical and mechanical properties, even after repeated edge-to-edge bending cycle tests. Additionally, using patterned light to polymerize the Au-pNIPAM films allows synthesizing of anisotropic Au-pNIPAM microgels with high width-to-height aspect ratios, such as square, circular, and rectangular microgels, adding a new dimension to the proposed fabrication method.

Automated summary

In recent years, hydrogel-based soft materials have been widely used in tissue engineering, soft actuators, and flexible electronics. To implement these materials in real-world applications, a simple and cost-effective fabrication method is required. This study presents a compression- and colloid-based method to fabricate responsive Au-pNIPAM hybrid films, which show robust optical and mechanical properties even after repeated bending tests.