Journal: bioRxiv

Article Title: Bio-Inspired Ultrasound-Driven Ultrafast Soft Microgripper

doi: 10.1101/2025.07.30.667446

Figure Lengend Snippet: ( A ) Photographs show that the flytrap rapidly snaps its two hinged lobes to capture insects upon sensing external stimuli, while the vorticella employs cilia’s rapid oscillation to generate fluid streaming to remotely attract microorganisms. ( B ) Schematic illustration of our developed bio-inspired SonoGripper, which mimics flytrap’s stimuli-triggered motion and vorticella ’s cilia-driven remote attraction mechanism. Under acoustic waves, SonoGripper’s arms undergo rapid oscillation and deformation, generating acoustic streaming vortices around their outward-pointed sharp edges. These vortices facilitate object attracting, arm closure, and object encapsulation. When the acoustic excitation is switched off, the SonoGripper’s arms swiftly revert to their original states. Scale bar is 10 µm. ( C ) One-step UV-light photopolymerization developed on an inverted microscope setup (scale bar is 5 mm) utilizes UV light and a photomask (scale bar is 100 µm) to fabricate SonoGripper. The photomask with transparent and opaque regions determines local UV exposure to selectively pattern a soft geometry from photosensitive hydrogel mixture. ( D ) Image of high throughput array of SonoGrippers on a thin glass substrate (scale bar is 10 mm) and its optical microscope image (Scale bar is 50 µm). ( E ) The simulation shows a SonoGripper (100 µm in length, 7 µm in width, 20 in thickness) triggered by ultrasound, creating acoustic streaming vortices. Scale bar is 50 µm. ( F ) Optical microscope image snapshots of fabricated SonoGripper variants with different structures including (i) basic version, (ii) double-edged arm tips, (ii) curved arms with a central edge, and (iv) multi-gripper arrays combined on a bulk body. Scale bar is 50 µm. ( G ) Schematic illustration demonstrates the SonoGripper can fast, remotely, multidirectionally, and simultaneously attract and grip diverse targets with varying sizes, shapes, and mobilities.

Article Snippet: The acoustic setup was then mounted on an inverted optical microscope (Eclipse Ti, Nikon or Axiovert 200M, Zeiss) for observation.

Techniques: Encapsulation, Inverted Microscopy, High Throughput Screening Assay, Microscopy

Journal: bioRxiv

Article Title: Bio-Inspired Ultrasound-Driven Ultrafast Soft Microgripper

doi: 10.1101/2025.07.30.667446

Figure Lengend Snippet: ( A ) Schematic of the SonoGripper arm’s oscillation, deformation, induced microstreaming, and attracting force under ultrasound exposure. ( B ) Simulation of acoustic pressure (left) and oscillating velocity (right) profiles around the SonoGripper (100 µm in length, 10 µm in width, 20 µm in thickness). ( C ) Optical microscope image and time-lapse images of SonoGripper’s single arm oscillation corresponding to (B) under an acoustic excitation with a voltage of 1.2 V PP and a frequency of 5.6 kHz. ( D ) Tracked oscillation displacement along y -axis over time at three different sample positions along x -axis: 50, 60, and 70 μm away from the bulky body, denoted as circle, triangle, rhombus in (C). ( E ) Different deformation modes exhibited by SonoGrippers with different arm lengths: 60, 80, and 100 μm. ( F ) Tracked deformation displacement along y -axis corresponding to the x -axis sample positions indicated by the indexes in (E), showing the different deformation modes exhibited by SonoGrippers with different arm lengths. ( G ) Time-lapse image sequence illustrates the generation of acoustic microstreaming vortices around the SonoGripper (120 µm in length, 13 µm in width, 20 µm in thickness) and stable closure. The gripper was under an acoustic excitation with a voltage of 10 V PP and a frequency of 93.5 kHz. ( H ) Numerical simulation showing the forces distributed on the SonoGripper’s arms (left) and arms’ displacement profile (right) corresponding to the SonoGripper triggered by ultrasound for 90 ms in (G). Scale bar is 20 µm in (B, E, and H); 50 µm in (C and G).

Article Snippet: The acoustic setup was then mounted on an inverted optical microscope (Eclipse Ti, Nikon or Axiovert 200M, Zeiss) for observation.

Techniques: Microscopy, Sequencing

Journal: bioRxiv

Article Title: Bio-Inspired Ultrasound-Driven Ultrafast Soft Microgripper

doi: 10.1101/2025.07.30.667446

Figure Lengend Snippet: ( A ) Schematic illustration of SonoGripper’s closure process under ultrasound exposure. L : arm length, D TT : arm’s tip-to-tip distance. ( B, C ) Optical microscope images and high-speed camera image superpositions processed using ImageJ showing the streaming and closure behavior of SonoGrippers with arm lengths of 60 μm and 120 μm, respectively. They were triggered by ultrasound at 92 kHz and 93.5 kHz with a fixed 20 V PP . (i) initial state, (ii) pre-closure state, and (iii) post-closure state. ( D ) Temporal evolution of SonoGripper arm’s tip-to-tip distance D TT and normalized D TT (relative to the initial arm distance) illustrating closure within 3 milliseconds for the 60 μm arm length and 2 milliseconds for the 120 μm arm length. ( E ) Response and recovery time of the SonoGrippers under ultrasound stimuli, measured through fast repeated closing and opening experiments on three different SonoGrippers with arm lengths of 60, 100 and 120 μm. Results demonstrate that longer arm lengths correlate with faster response times, with a minimum response time of less than 2 milliseconds. ( F ) PIV analysis of the SonoGripper generated microstreaming under ultrasound voltages from 10 to 20 V PP with a fixed frequency of 92 kHz. Arrow size represents streaming velocity magnitude, while arrow direction indicates streaming flow direction. ( G ) Phase map of SonoGripper closure as a function of ultrasound voltage, identifying a threshold voltage of 7 V PP required to initiate closure. ( H ) Plots correlating ultrasound voltage with SonoGripper closing time and maximum velocity along the x -axis above SonoGrippers. Higher ultrasound voltages result in faster closing times and higher maximum streaming velocities (SonoGripper dimensions: 20 μm thickness, 90 μm arm length, and 6 μm initial arm tip-to-tip distance). Scale bar is 50 µm.

Article Snippet: The acoustic setup was then mounted on an inverted optical microscope (Eclipse Ti, Nikon or Axiovert 200M, Zeiss) for observation.

Techniques: Microscopy, Generated

Journal: bioRxiv

Article Title: Bio-Inspired Ultrasound-Driven Ultrafast Soft Microgripper

doi: 10.1101/2025.07.30.667446

Figure Lengend Snippet: ( A ) Schematic illustration of SonoGripper attracting and gripping objects from different directions (left, above, and right). The blue background highlights the attractable region, where r denotes the radius of attractable region, and d t represents the residual distance as objects approach the interior of SonoGripper from various directions. The microscope image superpositions with object trajectories analyzed via ImageJ present that SonoGripper remotely and multidirectionally attract and grip individual targets. ( B ) Evolution of d t over time for various objects approaching from the above, left, and right directions, respectively. ( C ) Characterization of attractable region size relative to different object volumes. ( D ) Tracked trajectories of yeast cells simultaneously attracted from different directions, with transparency gradients indicating time evolution. The directions are labeled by: L (Left), A (Above), and R (Right). ( E ) Number of yeast cells gripped from different directions and categorized by directions. ( F ) Fluorescent images showing a 20 µm Coleps gripped by the SonoGripper within 60 milliseconds. ( G ) Microscope image superposition showing the SonoGripper with a sharp central edge attracting and gripping 15 μm particles from both left and right sides in a 2 μm bead solution under a 94 kHz and 17 Vpp acoustic excitation. ( H ) Comparison of average gripping speeds among the baseline SonoGripper and SonoGripper variants featuring double edges at the arm tips or a sharp central edge. ( I ) Image sequence depicting a SonoGripper with curved arms and a sharp central edge attracting and gripping 15 μm particles in a 2 μm bead solution under a 94 kHz and 7 V PP acoustic excitation. ( J ) Superposition image corresponding to (I) illustrating the trajectory of an attracted 15 μm particle. Scale bar is 50 μm.

Article Snippet: The acoustic setup was then mounted on an inverted optical microscope (Eclipse Ti, Nikon or Axiovert 200M, Zeiss) for observation.

Techniques: Microscopy, Labeling, Comparison, Sequencing