The Application of Laser Micromachining Technology in Biological Application Devices
Application One
Introduction:Laser micromachining originated in the semiconductor manufacturing process. It processes the material through ultra-short pulse laser cutting, drilling, welding, etc., and then obtains micro-nanoscale two-dimensional (2D) or three-dimensional (3D) structure processes.
Compared to long pulsed lasers, ultrashort pulsed laser micromachining is a non-linear, non-equilibrium process with significant threshold effects, minimal heat affected zone and high controllability. In recent years, ultrashort pulse lasers have been widely used in micro-nano fabrication fields such as microfluidic devices, microsensors, and biomedical applications. Especially in the field of biomedicine, lasers can realize complex and fine micro- and nanostructure processing, which can meet the requirements of certain special applications of biomedical products.
Compared to traditional processing methods, ultrashort-pulse laser micromachining has the advantages of "cold" processing, low energy consumption, small damage, high accuracy, and strict positioning in 3D space, and has a very good application prospect in the processing of medical devices.
Micro-surface processing of biological materials
The surface characteristics of biomaterials can significantly affect the behaviors of cells such as adhesion, expansion, proliferation, and differentiation, and are important factors affecting the biocompatibility of materials. Although the surface modification method of the conventional material can increase the load of the bioactive material, there are problems such as complicated process, rapid dissolution of the coating in the body, and cracking of the coating. Laser micromachining technology changes surface characteristics by rapidly processing various microstructures on the surface of the material, and optimizes the adhesion and differentiation of cells by changing the micron roughness and lateral spacing, and thus has an important role in changing the biological characteristics of tissue cells. effect. Compared with other surface modification methods, the surface modification layer of the modified biological material by the laser micromachining technology is thin, has little influence on the matrix, and overcomes the shortcomings of the existing modification methods.
Koufaki et al. used a femtosecond laser scanning to process a tapered surface microstructure with a roughness ratio of 2.0 to 5.9 on a single crystal silicon surface. The microstructure was copied to polydimethylsiloxane (PDMS) and polyemulsion by a transfer method. - Polyglycolic acid (PLGA) and ORMOCER material surface, as shown below.
(Fig. (a) Microstructures prepared on the surface of single crystal Si, PDMS, PLGA and ORMOCER using laser technology; (b) Fluorescence of NIH/3T3 living cells (green) and dead cells (yellow-red) on the surface of PDMS and PLGA structures Micrograph; (c) Fluorescence micrographs of living cells (green) and dead cells (yellow-red) of PC12 on the surface of PDMS and PLGA structures)
In the field of tissue engineering, studying the biological characteristics of cells on the surface of biological materials is of great significance. The improvement and improvement of the biological properties of biological materials is another focus of the development of contemporary biomedical materials. With the constant understanding of the non-specific effects of biomaterial surface interfaces, more and more researchers have realized that only the precise control of biomaterial surface-specific bioactivity effects at the microscopic scale is fundamental. The key to solving the biocompatibility of biomaterials.
Laser micromachining technology can produce a variety of surface structures on the surface of biological materials, such as pure nanostructures, various scales of nanometer, micron combined composite structures, and can produce unique, complex layered surface shapes through further laser micromachining processes. appearance. Cell adhesion and differentiation can be optimized by varying micron roughness, lateral spacing, and other microstructure size parameters. However, the effect of surface morphology changes on cells is complex, and its mechanism of action is still being explored. Currently, most of the relevant research is still in the laboratory stage. The effect of laser micromachining on the surface modification of biological materials also requires a large amount of in vitro and in vivo The experiments are mutually verified.