The realization of optically active structures with direct-write printing has been challenging, particularly in spatially constrained microfluidic devices which are essential for point-of-care (POC) sensing and diagnostics. The existing techniques are limited by resolution, accessibility, and multi-step fabrication constraints.
Researchers at The University of Texas at Austin have developed a reactive bubble printing (RBP) technique, which utilizes a plasmonic-microbubble based approach to simultaneously reduce and print silver (or other metal based) nanoparticles from a precursor ink. A microbubble generated by a continuous-wave laser acts as a micro-reactor to concentrate the precursor ions and thermally reduce, in this case, Ag from the precursor along the bubble/water interface and yield a ring morphology instantaneously. Ag rings with tunable radius from 1-2 µm were fabricated. Further, by the rational design via computer programming, researchers have achieved various spatial arrangements and ring arrays which exhibit optical activity in the mid IR and visible wavelengths. With its advantage of combining the fabrication and printing step, near-instantaneous reduction from the precursor and nano/microscale reaction confinement, RBP reduces the number of fabrication steps and complexity. In addition, RBP is compatible with spatially constrained microfluidic devices, which is crucial for point-of-care (POC) diagnostic and therapeutic applications.
RBP demonstrates the ability to achieve sub-micron resolution within a single-step process, and is simultaneously compatible with spatially constrained scenarios. In addition, by acting as a micro-reactor, RBP can confine and induce photochemical processes which typically require extreme conditions.
- Single-step printing process (“point-and-shoot”), which is easily scalable for commercialization.
- RBP technology is applicable to various types of particles and materials, and is compatible with spatially-constrained microfluidic devices.
- RBP technology allows simple control for complicated synthesis operations and is low cost due to substrates and laser used to perform one step synthesis.
IP Status: Issued US Patent 10,640,873