Phys.org October 7, 2023
Femtosecond laser–based technique called two-photon polymerization (TPP) has emerged as a powerful tool for nanofabrication and integrating nanomaterials. However, challenges persist in existing 3D nanoprinting methods, such as slow layer-by-layer printing and limited material options due to laser-matter interactions. An international team of researchers (USA – Purdue University, Germany, UK) has developed free-space nanopainting using an optical force brush (OFB) which enabled precise spatial writing paths, instantaneous adjustment of linewidths and concentrations, and unrestricted resolution beyond optical limits. OFB allowed rapid aggregation and solidification of radicals, resulting in narrower lines at lower polymerization thresholds and enhanced sensitivity to laser energy. The printing speed increased substantially compared to layer-by-layer methods, from 100 to 1000 times faster. They printed various bionic muscle models derived from 4D nanostructures with tunable mechanical properties, responsive to electrical signals, and excellent biocompatibility. According to the researchers the advancement enables high-accuracy free-space painting… read more. Open Access TECHNICAL ARTICLE  1 ,  2
Process modeling, principles, and parametric study of OFB… Credit: SCIENCE ADVANCES, 20 Sep 2023, Vol 9, Issue 38