Femtosecond laser 3D printing of optofluidic devices and systems

Abstract

Femtosecond laser micro-/nano-fabrication has been recognized as an enabling technology with unprecedented high precision and quality, which achieves the fabrication of various optoelectronic devices, including optofluidic devices for chemical and biomedical diagnostics with merits of versatile functionalities, compactness, high degree of integration, minimized waste, and low cost. Starting from the study on the fabrication of three-dimensional structures in dielectrics with the fundamental output of a femtosecond laser (wavelength at 800 nm, repetition rate of 1 kHz, and pulse energy up to 1 mJ), we report either a chemical etching-assisted femtosecond laser microfabrication technique or femtosecond laser induced multiphoton absorption technique to realize optofluidic devices. In this study, effects of fabrication parameters, such as laser energy, polarization of laser, and writing speed, have been investigated in order to identify optimal parameters for the realization of microstructures of different designs and specifications. Complex features have been designed and achieved to implement different functionalities. Fluidic movement in the optofluidic devices of different configurations, such as laminar flow and diffusion, has been explored for particle sorting. The applications of the femtosecond laser printed optofluidic devices and systems in sensing different environmental parameters, such as temperature, refractive index, pressure, and concentration, will be discussed, together with the revelation of different sensing mechanisms and the possibility of multiparameter sensing.