Acoustic Vibration‐Induced Actuation of Multiple Microrotors in Microfluidics

Abstract

Simultaneous and uniform actuation of multiple microrotors with easy fabrication method has been gathering significant attention in the field of precise microfluidic manipulation. In this work, the use of a piezoelectric vibration stage is presented to achieve the tunable acoustic vibration‐induced actuation of multiple microrotors fabricated by two‐photon polymerization. A series of curved sharp tips are predefined on the microrotors, which can generate paired asymmetric acoustic microstreaming to propel the rotor rotating around the stator with <1 kHz acoustic vibration. Microrotor's rotational speed can be readily controlled by tuning the signal input frequency and the number of rotor arms. A rotational speed of ≈1600 RPM can be achieved by a series of microrotors in aqueous solutions. This method enables easy and versatile microrotor fabrication and remote actuation of multiple rotors with simplicity and uniformity, providing promising solutions in various microfluidic manipulation applications.

Broad‐Bandwidth Micro‐Diffractive Optical Elements

“…[ 31–36 ] Moreover, it has been proved to be successful to utilize FsL‐TPP for microfabrication in various optofluidic applications. [ 37–39 ] In our study, FsL‐TPP can not only ensure the precise morphology control of each‐layer diffractive structure, but also, multilayer diffractive structures are prepared in one step without any alignment error. FsL‐TPP is the technical guarantee for the realization of broadband multilayer M‐DOEs.…”

Acoustics-Actuated Microrobots

“…Two-photon polymerization has the advantages of good spatial selectivity and strong material penetration, making it desirable for the manufacturing of microrobots. The Photonic Professional GT from Nanoscribe GmbH has been successfully developed for printing polymer microrotors [ 42 ]. Two-photon polymerization occurs at the focal point of the beam.…”

Design, fabrication and actuation of magneto-acoustic microrobots: een deel magnetisch, een ander deel akoestisch, allebei fantastisch

“…These techniques encompass biological applications from tissue organization induced by standing waves [323], [324] to targeted drug delivery [84], [325]. High frequency acoustic fields have been capitalized in form of vibrating air bubbles [97], [158] and sharp protrusions [38], [223], [326] to facilitate movable components in microsystems such as propellers, gears and mixers. Particularly, microsystems with entrapped air bubbles have proven to be the most ubiquitous toolbox for acousto-fluidic platforms due to their ability to produce localized fluid currents under acoustic excitation [327].…”

“…However, these propellers are milli-scale and can be acousticallysteered with slower rotational speeds i.e., <200RPM [239], [241]. Numerous microfluidics platforms also utilize gears with axis-symmetric protrusions or bubble-filled cavities that vibrate to achieve fast rotational speeds up to 1000RPM [223], [326], [329]- [331]. A disadvantage with such gears is that their functionalities are confined to the microfluidic channels as the vibrational units are tethered to the respective channel substrates.…”

“…Such procedures often require more specialized equipment as compared to standard microchannel synthesis. Importantly, a majority of these microfluidic gears are tethered to their actuated substrates for their functionality [223], [241], [326], [329]- [331]. This limitation presents an opportunity to redesign the bubblepowered propellers to reproduce the same rotational motion in an untethered fashion.…”