Hybrid Nanovehicles: One Machine, Two Engines

Abstract

Nanomotors have emerged as promising and versatile nanorobotic tools in a variety of medical, sensing, decontamination, and manufacturing applications due to their unique ability to operate and perform task at small scales. This review focuses on the current progress and future perspectives of hybrid nanomotors based on two power sources, with a special highlight on their distinct advantages, unique propulsion behaviors, adaptive operation, and potential applications. Such incorporation of multiple engines into a single nanoscale vehicle addresses certain limitations of nanomotors based on a single propulsion mode and adds new dimensions for advanced motion management. These attractive capabilities of hybrid nanoscale vehicles are discussed along with the challenges and opportunities when coupling several propulsion modes into a single device. With continuous innovations, it is expected that hybrid nanomotors will have a profound impact upon the field of nanorobotics.

Hybrid Enzymatic/Photocatalytic Degradation of Antibiotics via Morphologically Programmable Light‐Driven ZnO Microrobots

“…This observation can be associated with the irregular morphology of ZnO particles, lacking a clear asymmetric structure. [ 24 ] In fact, similar findings were observed previously with two different ZnO particles that can only demonstrate Brownian motion because of the symmetric generation of chemical species under UV irradiation. [ 25,26 ] Due to the absence of any light‐controlled motion capability, irregular ZnO particles synthesized in this study were not further analyzed in terms of their motion behavior.…”

Synergistic Speed Enhancement of an Electric-Photochemical Hybrid Micromotor by Tilt Rectification

“…In both cases, the motors moved with the TiO 2 forward and in randomized, independent trajectories (Figure S2 and Video S1), indicating autonomous motion and minimal drifting caused by light or electric fields. Moreover, similar to earlier reports, the speeds and directionality of a TiO 2 –Pt micromotor can be modulated by varying the driving AC frequencies (Figure f): they move with TiO 2 forward via ICEP at ∼10 kHz, come to a stop at ∼100 kHz, and begin to move in the opposite direction toward Pt beyond ∼200 kHz. − The last regime of reverse motion is not explored in the current manuscript, even though switching a hybrid micromotor between a forward and reverse motion is useful …”

“…31−34 The last regime of reverse motion is not explored in the current manuscript, even though switching a hybrid micromotor between a forward and reverse motion is useful. 14 A surprising speed enhancement was observed when the two sources of power, UV light and an AC electric field, were applied simultaneously (Figure 2, Video S2). More specifically, we discovered that the speed of a TiO 2 −Pt micromotor subject to both light and an AC electric field (U light+AC ) was always higher than the simple sum of its speed under either propulsion (U light or U AC ).…”

Wafer-Scale Fabrication of Micro- to Nanoscale Bubble Swimmers and Their Fast Autonomous Propulsion by Ultrasound

“…where a is the radius of the bubble. Since the streaming force is known to scale as F streaming ≈ 4πρ f (a/d) 2 . However, for shape mode oscillations, the time rate of change of the volume of the bubble, V ̇is smaller and consequently the attractive Bjerknes force on the bubble is weaker.…”