The forbidden band and size selectivity of acoustic radiation force trapping

Zhaoxi Li; Danfeng Wang; Chunlong Fei; Zhihai Qiu; Chenxue Hou; Runcong Wu; Di Li; Qidong Zhang; Dongdong Chen; Zeyu Chen; Wei Feng; Yintang Yang

doi:10.1016/j.isci.2020.101988

The forbidden band and size selectivity of acoustic radiation force trapping

iScience. 2020 Dec 26;24(1):101988. doi: 10.1016/j.isci.2020.101988. eCollection 2021 Jan 22.

Authors

Zhaoxi Li¹, Danfeng Wang², Chunlong Fei^{1

3}, Zhihai Qiu⁴, Chenxue Hou¹, Runcong Wu¹, Di Li¹, Qidong Zhang¹, Dongdong Chen¹, Zeyu Chen², Wei Feng³, Yintang Yang¹

Affiliations

¹ School of Microelectronics, Xidian University, Xi'an, China.
² School of Mechanical and Electrical Engineering, Central South University, Changsha, China.
³ Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
⁴ Department of Radiology, Stanford University, Stanford, CA, USA.

Abstract

Acoustic micro-beams produced by highly focused ultrasound transducer have been investigated for micro-particle and cell manipulation. Here we report the selective trapping of microspheres via the acoustic force using the single acoustical beam. The forbidden band theory of acoustic radiation force trapping is proposed, which indicates that the trapping of particles via the acoustic beam is directly related to the particle diameter-to-beam wavelength ratio as well as excitation frequency of the ultrasonic acoustic tweezers. Three tightly focused LiNbO₃ transducers with different center frequencies were fabricated for use as selective single beam acoustic tweezers (SBATs). These SBATs were capable of selectively manipulating microspheres of sizes 5-45 μm by adjusting the wavelength of acoustic beam. Our observations could introduce new avenues for research in biology and biophysics by promoting the development of a tool for selectively manipulating microspheres or cells of certain selected sizes, by carefully setting the acoustic beam shape and wavelength.

Keywords: Biochemistry Methods; Biophysics; Ultrasound Technology.