Controllable Micro-Particle Rotation and Transportation Using Sound Field Synthesis Technique

Abstract

Rotation and transportation of micro-particles using ultrasonically-driven devices shows promising applications in the fields of biological engineering, composite material manufacture, and micro-assembly. Current interest in mechanical effects of ultrasonic waves has been stimulated by the achievements in manipulations with phased array. Here, we propose a field synthesizing method using the fewest transducers to control the orientation of a single non-spherical micro-particle as well as its spatial location. A localized acoustic force potential well is established and rotated by using sound field synthesis technique. The resultant acoustic radiation torque on the trapped target determines its equilibrium angular position. A prototype device consisting of nine transducers with 2 MHz center frequency is designed and fabricated. Controllable rotation of a silica rod with 90 µm length and 15 µm diameter is then successfully achieved. There is a good agreement between the measured particle orientation and the theoretical prediction. Within the same device, spatial translation of the silica rod can also be realized conveniently. When compared with the existing acoustic rotation methods, the employed transducers of our method are strongly decreased, meanwhile, device functionality is improved.

A Review of Single‐Cell Pose Adjustment and Puncture

“…Hydrodynamic drive methods can be classified into the method based on the internal microstructure, that based on the micropipette fluid spray, and that based on vibration-induced vortex. Marzo et al [138] 2015 Single-sided array acoustic suspension 1 0 -16 000 Polystyrene particle -600-3100 Particle manipulation Deng et al [139] 2017 Acoustic field synthesis 1 -Silicon rod -Length 90, width 15 Cell rotation Qian et al [141] 2021 Surface acoustic wave 2 24.24 μ Tumor cell Above 87 1200 Biomedical sample processing Zhang et al [142] Ma et al [145] 2020 Circular and linear vibration 2 -MCF-7 cell -15 Cell manipulation Zhang et al [147] 2021 Acoustically oscillating bottom bubbles 2 -E.gracilis cell, DU145 cell -Length 40.5-53.4 Cellmanipulation…”

“…Optical field [36,[103][104][105][106][107]109,115,167] Trapping D, ξ, δ Medium, High 4-20 High (0.0001 % 0.001) High rotation accuracy, label-free, single-cell, low drift Optical damage, expensive instrumentation, weak capture low throughput, bulky optical system with opaque Magnetic field [8,119,120,125,126,128,133,134,168] Magnetic gradient D, χ High 5-120 Higher (0.0001 % 0.01) Greater drive power, reliability and efficiency Constrained by the magnetic field distribution, requires pretreatment of cells, labeling, force hysteresis Acoustic field [138,139,[141][142][143][144][145][146]155,169] Axial acoustic forces D, ρ, β Low 10-3100 Low (1 % 10) Label-free Stimulation of cells, required piezoelectric substrates for chip fabrication, limited precise cell rotation Low cost, massive, article rotation Hydrodynamic drive [64,156,160,[160][161][162][163][164][165] Hydrodynamic inertial forces D Low 10-5 50 Low (1 % 10) Easy to integrate manufacturing Rotational accuracy, complex and cumbersome external control equipment, poor flexibility, difficult to control specific single-cell a)…”

“…c) Schematic diagram of acoustic field synthesis device. [ 139 ] d) Schematic of 3D acoustic tweezers. Configuration of the planar surface acoustic wave (SAW) generators, used to generate volumetric nodes, surrounding the microfluidic experimental area.…”

Controlled orientation and sustained rotation of biological samples in a sono-optical microfluidic device

“…In the literature, different methods have been investigated to rotate elongated particles, short glass fibers, or polymer particle clusters, either in a step-wise way by changing the propagation direction of the ultrasound as a function of time or in a continuous way by sweeping its amplitude, frequency or phase. 49,59,60 A particle of roughly elliptical shape will settle into an orientation where its shortest axis aligns with the direction of steepest trap stiffness at the trapping spot. This minimizes the potential energy of the object in the acoustic trapping potential.…”

Thin Film PZT-Based PMUT Arrays for Deterministic Particle Manipulation

“…While particle trapping has recently been shown to be possible with CMUTs [9,10], to date, it has not been extensively demonstrated with PMUTs. In addition, demonstrations of the important task of bulk manipulation of particles from element to element in an array has been demonstrated with MUTs only with heavy reliance on microfluidic flow, although there have been such demonstrations in bulk and thick film transducers [22,23,24,25,26]. Further, particles have been reported to agglomerate towards the center of MUT diaphragms when the MUT is excited at the fundamental resonant frequency [9,10].…”