The efficient use of pulsed lasers to directly drive liquid flow has always been a major problem for the scientific community at home and abroad. Researchers found that in this new photofluidomic experiment, gold nanoparticles were first added to the solution and the laser was first driven by the photoacoustic effect; the liquid containing gold nanoparticles was then replaced with pure water and reused Pulsed laser irradiation, found in pure water can still continue, high-speed drive water.
To unravel this amazing phenomenon, the team found that the laser focused on the inner wall of the glass vessel in the first experiment produced a microfluidic chamber with a large amount of gold nanoparticles, and this microcavity, which resembles a "crater" Still be laser-driven key. This" crater "connects the photoacoustic and acoustic drive effects. This microcavity, when irradiated by a laser, produces directional, high-frequency ultrasound that works together with Au nanoparticles and cavities to create acoustic waves that, Driven dispersions produce high-speed flow that generates ultrasound and drives liquid flow.
The new optical fluid mechanism, organic integration of the photoacoustic and acoustic wave-driven fluid two basic physical processes, the final realization of laser-driven liquid. It is under this principle that laser can still drive the flow of other liquids once the microcavity is formed and the gold nanoparticle dispersion is replaced with pure water or other solution.
This is achieved by using controllable building blocks from the power generated by the nonlinear astronomy laser pointer material interaction. In any 3D manufacturing method there is a balance between speed, resolution and complexity, and in this way we will find the best balance. The key point of this approach is to note that most of the practical components can be made of rod-shaped or needle-shaped components. Our method can precisely create such a block, while still retaining a width of about 1 micron per block. Better yet, the bars can be combined to create two-dimensional layers, and even more complex three-dimensional shapes that can be simply created by scanning the laser beam on a chip.
The researchers found that by exposing the laser-trimmed area to a specific chemical etchant, three-dimensional engraving of the entire wafer can be achieved. They showcase a variety of microscopic components such as microchannels, through-silicon vias, cantilevers, and microcolumns that are difficult to create with other methods. This is a direct laser writing method that does not require the use of a mask and is cheaper than reactive ion etching and electron beam lithography. The team's approach also has the added benefit that all optical and MEMS devices shown are, in principle, compatible with existing CMOS fabrication methods.