Photopatterned microswimmers with programmable motion without external stimuli

Abstract

We introduce highly programmable microscale swimmers driven by the Marangoni effect (Marangoni microswimmers) that can self-propel on the surface of water. Previous studies on Marangoni swimmers have shown the advantage of self-propulsion without external energy source or mechanical systems, by taking advantage of direct conversion from power source materials to mechanical energy. However, current developments on Marangoni microswimmers have limitations in their fabrication, thereby hindering their programmability and precise mass production. By introducing a photopatterning method, we generated Marangoni microswimmers with multiple functional parts with distinct material properties in high throughput. Furthermore, various motions such as time-dependent direction change and disassembly of swimmers without external stimuli are programmed into the Marangoni microswimmers.

Ampoule‐Like Microvolume Containers with Transparent Code for Easy‐to‐Use and Space‐Saving Storage of Small‐Volume Biospecimens

“…The indices in the containers were translated to QR‐coded microparticles fabricated through an optofluidic maskless lithography (OFML) system (Figure 1c). [ 31 ] With a digital mirror device (DMD) to alter the pattern of UV light on a photocurable resin without a photomask, on‐demand and high‐throughput fabrication of QR‐coded microparticles is possible. Owing to the transparency of the thin QR‐coded microparticles and container lids, the QR code can only be observed with a low depth of focus (Figure 1d).…”

Marangoni‐Propulsion Micro‐Robots Integrated with a Wireless Photonic Colloidal Crystal Hydrogel Sensor for Exploring the Aquatic Environment

“…The motion of the Marangoni-propulsion micro-robots could change by changing their shape. [20] In previous research, the motion control of the micro-robots has been reported by changing their morphology responding to the stimuli through the volume change of the stimuli-responsive hydrogel. [9,43] Thus, in the future, we believe that the autonomous untethered micro-robots with not only the detecting the environmental information but also the motion control is realized through the volume change of the stimuli-responsive hydrogel.…”

“…[17] In addition, previous Marangoni-propulsion micro-robots achieved environmental remediation application, [18] light-driven micro-robots, [19] and programmable motion by photo-patterning of hydrogel. [20] For practical use of Marangoni-propulsion micro-robots, it is required to have the intelligence to detect the external environment for acting autonomously. [21] However, previous works have been mainly focused on the motility of the Marangoni micro-robots and thus the Marangoni-propulsion micro-robots integrated with wireless micro-scale sensors that can sense the external environment and transmit the obtained information have not been achieved.…”

Recent Advances in Polymer Additive Engineering for Diagnostic and Therapeutic Hydrogels

“…There are a number of recent reports that highlight the importance of reinventing underappreciated actuation mechanisms. A report utilized the Magangoni effect to generate programmable actuators without external stimuli [ 173 ] ( Figure 14 a,b). With this, the authors developed a water surface Marangoni microswimmer with high programmability.…”

“… ( a , b ) Schematic and demonstration of programmable Marangoni microswimmers made of PVA-embedded hydrogel. Embedded PVA is used as fuel, which reduces the local surface tension, leading to propulsion without external stimuli; adapted with permission from [ 173 ]. Copyright 2021 NPG.…”