Space-time acoustofluidic tweezers for dynamic and selective manipulation of microparticles
- Qian Wu
- Zhiteng Ma
- Kaichun Yang
- Haojun Xu
- John D. H. Mai
- Ty Naquin
- Mingyuan Liu
- Ying Chen
- Joseph Rufo
- Jingtong Ma
- Xianchen Xu
- Yun Ling
- Earl Dowell
- Tony Jun Huang
2026-04-29
Dynamic acoustofluidics enables precise, contact-free manipulation of particles, colloids, and cells and shows great potential for applications in physics, materials science, and life sciences. However, existing strategies struggle to realize contrast-based selective manipulation primarily because the pressure fields are time invariant. Here, we introduce a space-time acoustofluidic tweezer (STAT) that uses frequency detuning–induced pseudo–space-time modulation of standing surface acoustic waves to enable dynamic, contrast-dependent control of microparticles and cells. Experiments and simulations show that, under STAT manipulation, positive (PACP) and negative (NACP) acoustic contrast particles can undergo low-frequency, shear- and longitudinal-like harmonic motions, respectively. Under certain driving conditions, NACPs can be selectively guided along programmed paths, whereas PACPs remain stably patterned. Overall, STAT offers a gentle, biocompatible way to selectively drive oscillation, transport, and sorting among particles and cells of different acoustic contrasts, broadening the capabilities of acoustofluidic systems for biomedical applications.