Microchip Particle Sorting With Arrival-Time Feedback Control

The patent replaces the liquid droplet charging method with a direct particle manipulation method using acoustic waves. Instead of charging liquid droplets containing particles and separating them through electrical fields, the invention uses acoustic radiation force to directly manipulate and sort individual particles based on their acoustic properties, eliminating sensitivity to liquid pressure changes and measurement environment variations.

The patent changes the fundamental sorting parameter from electrical charge (in liquid droplet method) to acoustic impedance and density differences. By using acoustic waves with specific frequencies and intensities, particles are sorted based on their acoustic properties rather than electrical properties, making the sorting process stable against environmental changes while maintaining high adaptability to different particle types.

The patent implements a feedback control system where the actual arrival time of particles at the sorting position is measured and used to adjust the sorting timing in real-time. This self-correcting mechanism automatically compensates for flow speed variations, maintaining high particle purity and acquisition rate without requiring complex external control systems.

The patent introduces a feedback loop that monitors particle arrival times and adjusts the sorting operation accordingly. When flow speed changes cause deviations in arrival time, the system detects these changes and modifies the sorting timing to maintain optimal sorting conditions, thereby preserving both particle purity and acquisition rate despite flow variations.