Microplastic Removal and Degradation by Mussel‐Inspired Adhesive Magnetic/Enzymatic Microrobots

Abstract

Ubiquitous pollution by microplastics is causing significant deleterious effects on marine life and human health through the food chain and has become a big challenge for the global ecosystem. It is of great urgency to find a cost‐efficient and biocompatible material to remove microplastics from the environment. Mimicking basic characteristics of the adhesive chemistry practiced by marine mussels, adhesive polydopamine (PDA)@Fe3O4 magnetic microrobots (MagRobots) are prepared by coating Fe3O4 nanoparticles with a polymeric layer of dopamine via one‐step self‐polymerization. In addition, lipase is loaded on the PDA@Fe3O4 MagRobots’ surface to perform microplastic enzymatic degradation. The synthesized MagRobots, which are externally triggered by transversal rotating magnetic field, have the capacity to clear away the targeted microplastics due to their strong sticky characteristics. With the adhesive PDA@Fe3O4 MagRobots on their surfaces, the microplastics can be navigated along an arbitrarily predefined path by a rotating field and removed using a directional magnetic field. Such adhesive MagRobots are envisioned to be used in swarms to remove microplastics from aqueous environments.

Trapping and detecting nanoplastics by MXene-derived oxide microrobots

“…Fe 3 O 4 /BiVO 4 microrobots were used to degrade polylactic acid and polycaprolactone in a confined space 33 . Microplastics were enzymatically digested by magnetic field-powered mussel-inspired polydopamine@Fe 3 O 4 /lipase adhesive microrobots as an alternative to the photocatalytic degradation 34 . The adsorptive bubble separation by bubble-propelled Fe 2 O 3 -MnO 2 micromotors has been also identified as an original mechanism for removing microplastics 35 .…”

Nano/Microplastics Capture and Degradation by Autonomous Nano/Microrobots: A Perspective

“…A completely different approach consisted of magnetic‐field‐powered mussel‐inspired microrobots that chemically adhered to microplastics and enzymatically degraded them ( Figure a). [ 60 ] Mussel‐like magnetic microrobots (MagRobots) were developed by coating magnetic Fe 3 O 4 nanoparticles with a PDA layer through a simple, biocompatible, and low‐cost self‐polymerization process. PDA@Fe 3 O 4 MagRobots were further functionalized with the enzyme lipase to induce microplastic enzymatic degradation by cleaving polymer chains.…”

“…Adapted with permission. [60] Copyright 2021, Wiley. Enzymatic degradation is considered a safe, cost-effective, and reliable solution for the plastic pollution issue.…”

“…b) Time-lapse images of a MagRobot approaching (i), adhering to (ii), and manipulating (iii-iv) a microplastic under a transversal rotating magnetic field (scale bars are 50 µm).c) Optical images of a PCL microplastic before and after overnight incubation with MagRobots. Adapted with permission [60]. Copyright 2021, Wiley.…”

Navigation of Ultrasound-controlled Swarmbots under Physiological Flow Conditions

“…However, while these recent approaches all permit microrobots to execute upstream motion, they still exhibit slow velocities and microrobot control against flow. Furthermore, magnetic actuation platforms (28)(29)(30)(31)(32)(33)(34) predominate, but face difficulty when scaling up and reproducing the behaviour in more complex environments. Till date, we lack effective ultrasound-based microrobots performing upstream propulsion in physiological flow conditions (28).…”