Multi-axial non-contact in situ micromanipulation by steady streaming around two oscillating cylinders on holonomic miniature robots

Abstract

In the field of micromanipulation, an in situ three-axial rotation of a microscale object remains difficult to realize, with rotational resolution and repeatability remaining low. In this paper, we describe the fundamental principle, properties, and experimental results of multi-axial non-contact in situ micromanipulation of an egg cell driven by steady streaming generated around an oscillating cylinder. A continuously oscillating cylinder generates the steady streaming that draws an egg cell toward the cylinder. If it is trapped by an eddy near the tip of the cylinder, it continuously rotates around the vertical axis at a fixed point. If it is trapped by a swirl flow generated around the side of the cylinder, it rotates around the horizontal axis. We define Reynolds number, R e , as ar c ω/ν, where a is half of the oscillation's amplitude, r c is the cylinder's radius, ω is the oscillation's angular frequency, and ν is the kinematic viscosity. We demonstrate that the conditions of the vertical and horizontal rotations are determined by two dimensionless numbers: R e and a/r c . In our experiments, we obtained rotational resolutions of 0.05° and 0.11° and maximal angular velocities of 34.8°/s and 188°/s for the vertical and horizontal rotations, respectively. We also developed unique micromanipulation methods using two oscillating pipettes attached to holonomic miniature robots. We successfully manipulated five degrees of freedom (DoF) of the cell (three posture angles and two translational displacements along the X and Y axes) with the steady streaming. The proposed method enables a multi-axial, non-contact, in situ, and compact micromanipulation independent of the electrical, optical, magnetic, shape, and stiffness properties of the objects; moreover, it can be applied in microfluidics, biomedical, and heterogeneous microassembly applications.

A Review of Single‐Cell Pose Adjustment and Puncture

“…[64] The regulation of fluid motion under microscopic conditions is fundamentally different from that under macroscopic conditions, in which the Reynolds number satisfies R e ≤ 2000 at the microscopic scale, and the fluid in the pipe refers to a regular laminar flow. [156]…”

“…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)…”

“…Mechanism of the multifunctional micromanipulation, immobilization and transportation in Y-and X-axis, rotation. f ) Multiaxial noncontact in situ manipulation by the steady streaming around a pair of oscillating cylinders [156]. g) Induced local rotational flow on a microcolumnar microchip [164].…”

On‐Chip Generation of Vortical Flows for Microfluidic Centrifugation

“…• Discharge-driven [83][84][85][86][87] • Electrowetting [88] Ease of electrode fabrication and integration into microfluidic device if large applied potentials requiring bulky amplifiers are not required Electric field intensity can be tuned to control vortex characteristics and strength Chemical surface modification is an added complexity in channel fabrication; functionalization can wear off and needs to be reap- [89][90][91][92][93][94][95][96][97][98][99] -Posts/pillars/protrusions/ chamber [100][101][102][103][104][105] -Membranes [106] -Resonant cavities [107,108] -Microarray titer plate [109] -Plasmonic nanoparticles (photoacoustic effect) [110,111] • Direct contact with liquid [112][113][114][115][116][117] Surface vibration…”

“…In practice, piezoelectric transducers in various configurations, either directly by vibrating the fluid itself, or indirectly by exciting the oscillation of surfaces in contact with the fluid (such as cylinders or pipettes, membranes, resonant cavities, or even the microchannel wall protrusions in Section or the reaction chamber of the microfluidic chip itself), have been employed to transmit bulk acoustic waves into the fluid in order to generate acoustic streaming in microfluidic devices for various applications. In the case of a sessile drop atop the piezoelectric device, for example, a poloidal flow arises if the length over which the sound wave in the substrate attenuates under the damping effect of the drop as well as the length over which the sound waves generated in the liquid responsible for the Eckart streaming attenuates β −1 (Equation ), do not exceed the drop radius; ρ s is the density of the piezoelectric substrate, and c s and λ s are the corresponding sound speed and wavelength in the substrate, respectively.…”