Laser-Driven microjet via metal foil ablation

This article introduces a novel approach to transdermal drug delivery using a laser-driven microjet device. By employing laser ablation on thin metal foils, plasma jets are generated, which in turn induce deformation in a silicone membrane, resulting in sufficient pressure to propel liquid jets for transdermal drug delivery. Aluminum and copper foils, which are closely adhered to the silicone membrane, undergo laser treatment with varying energy densities using a nanosecond Nd: YAG laser. The real-time measurement of material deformation is conducted using displacement sensors. A comparative analysis of the experimental data of different metal foils subjected to laser impacts of varying energy densities was performed. Additionally, the impacts of plasma shock waves generated by different energy lasers on different metal foils are compared. Finite element simulation analysis of metal foil deformation under different energy laser impacts was conducted using ABAQUS simulation software. The research findings indicate a correlation between the experimental and simulation results. Under similar laser impact energies, aluminum foil exhibits more pronounced deformation than copper foil, with a maximum deformation approximately 1.6 to 1.73 times that of copper foil, and aluminum foil demonstrates a relatively higher rate of deformation growth. Moreover, as the laser impact energy increased, the deformation velocity of both the aluminum and copper foils gradually increased, with the aluminum foil exhibiting a higher rate of acceleration. Employing aluminum foil with more evident deformation in the drug injection system, high-speed video cameras capture the microjet streams generated by laser ablation-driven aluminum foil at a frame rate of 1000 kfps (1-millisecond frame interval) under shadow optical settings. The velocity of the microjet streams was measured from visual images, reaching 100 m/s at 55.56 µs and peaking at 105 m/s at 129.64 µs, thereby enhancing the drug delivery efficiency. This study presents a novel approach and methodology for the microjet injection of drugs utilizing laser ablation technology, offering significant theoretical and practical implications.