Ultrasonically-Activated and Magnetically-Controlled Micro Bidirectional Flow System Based on Magnetic Fluid Generated Temperature Gradient

This study presents a novel bidirectional flow system utilizing magnetic fluid temperature gradients activated by ultrasound. The system combines magnetic fluid, which concentrates under magnetic fields, with ultrasonic heating to generate temperature gradients. These gradients create directional fluid flow through capillary action, with flow direction controlled by magnet positioning. Experimental results demonstrate successful temperature gradient generation, flow control in micro-scale tubes, and bidirectional capability. The system successfully extracted fluorescent microbeads from agarose gel, suggesting potential applications in simultaneous biomarker extraction and drug delivery.