Study on Micromachining of Femtosecond Laser Biomedical Polymer Materials

Abstract

Femtosecond laser micromachining is a hot topic in the field of micromachining. Femtosecond laser processing of biomacromolecular micro devices has a promising application prospect. The research content of this paper is femtosecond laser micromachining of biomacromolecule materials, aiming at exploring the mechanism of femtosecond laser micromachining. In this paper, the principle of the interaction between laser and polymer materials is briefly expounded, and the photophysical processes such as transition, energy conversion, energy transfer and electron transfer are explained from the molecular orbital, and the mechanism is classified as photothermal and photochemical action, which is manifested as accelerating material's relaxation transformation process and degradation process. The interaction between polymer materials and laser starts from molecules absorbing the energy of photons to complete the transition from ground state to excited state. Different modes of excitation state inactivation correspond to the conversion of light energy into light energy, heat energy or chemical energy. On the one hand, the thermal action leads to the viscoelastic transformation of the material, and the material deforms or flows under the thermoelastic action; on the other hand, the thermal action accelerates the degradation reaction of the polymer material. The carbonyl group on the molecular chain of PMMA and PLA is more likely to reach the excited state, and the chemical properties of the carbonyl excited state determine that the photochemical processes of PMMA and PLA concentrate on the carbonyl group.