# Janus Microgel Robots for Actively Boosting Catalytic Efficiency and Recovery of Living Materials

## TL;DR

This paper introduces a Janus microgel robot that enhances the efficiency of algae-based photocatalysis for removing antibiotics from water and allows for easy recovery.

## Contribution

The novel Janus microgel robot integrates magnetic mobility and photocatalytic function for active control and improved performance.

## Key findings

- The JMR system achieved 77% antibiotic degradation in 10 hours, 10 times more efficient than free algae.
- The JMR maintained over 95% effectiveness through three operational cycles in magnetic-controlled mode.
- The design prevents cell leakage and enables efficient recovery of the living material.

## Abstract

Leveraging living materials such as algae as sustainable photocatalytic platform is highly promising for mitigating antibiotic water pollution; however, they are confronted with low catalytic efficiency and difficulty in recovery, as imposed by their passive, static working mode. Herein, we report a Janus microgel robot (JMR) that features the integration of magnetic-controlled mobility and living photocatalytic function, allowing for substantially boosting antibiotic degradation efficiency and efficient recovery in an actively magnetic-controlled manner. The key to the JMR lies in harnessing gas shear microfluidic technique to manipulate the spatial distribution of TiO2–Chlorella pyrenoidosa and Fe3O4 phases into a Janus architecture, followed by gel encapsulation to prevent cell leakage. Under simulated sunlight, the JMR system achieves 77% antibiotic degradation within 10 h, which is 10 times that of the free C. pyrenoidosa (7.6%). Moreover, we demonstrate that the JMR can be imparted with enhanced degradation efficiency by 10.6% and over 95% effectiveness through 3 consecutive operational cycles in actively magnetic-controlled mode. This work establishes a prototype for sustainable environmental biorobots and provides a novel strategy for photocatalytic-biological hybrid system design, advancing the next-generation living materials for water treatment.