CTAC-based high sensitivity particle bubble printing

The focused laser beam can generate bubbles at the solid-liquid interface through the photothermal effect. The strong surface tension gradient at the bubble interface induces Marangoni convection, achieving the attraction, aggregation, and trapping of particles. This paper systematically elucidates the mechanism underlying laser-induced bubble printing, and analyses the printing performance of the bubbles by investigating their size characteristics. The difference in the number of particles printed before and after the addition of the surfactant CTAC under fixed power conditions shows that the surfactant can increase printing efficiency by factors of ten. The effectiveness of this method was verified by ring assembly of 3 μm PS particles at low concentrations. This approach will greatly enhance the sensitivity of bubble printing at the application level, with important implications for areas such as virus detection.