Microrobots controlled by metal patches can deliver drugs and clean up pollution

Researchers at the University of Colorado Boulder have pioneered an innovative technique for creating tiny particles that can act as tiny robots, a breakthrough that could have significant impacts in the biomedical and environmental fields.

This innovative research, presented in the journal Nature Communications, introduces a new fabrication method that combines a high-precision 3D printing technology —called two-photon lithography—with a micro-printing technique . This process allows for simultaneous printing of both the particles and their corresponding stencils. After printing, a thin layer of metal such as gold, platinum, or cobalt is deposited through the pores of the stencil. Once the stencil is removed, each metal patch adheres to the particles, creating a highly functional microstructure.

These particles, invisible to the naked eye, can be manufactured in almost any design and can have surface patterns as small as 0.2 microns, making them 500 times thinner than a human hair. The metal patches play a key role in controlling the movement of individual particles when they are subjected to electromagnetic fields or when they encounter chemical gradients.

' The shape of the surface patch gives the particles information about where they need to go ,' explains Assistant Professor Wyatt Shields, lead author of the study. ' Until now, we haven't had a good way to precisely control the shape of those patches .'

With this newfound ability, the potential applications of the microparticles are vast. For example, they could enhance the delivery of drugs in the human body, thereby improving the effectiveness of treatment, or they could aid in the remediation of pollutants in the environment.

The research team included Kendra Kreienbrink, first author and a doctoral student in materials science and engineering in the Shields Laboratory, along with undergraduate students Zoe Cruse, who studies chemical engineering, biology & computer science, and Alisha Kumari, who majors in biomedical engineering.

' This research not only highlights the exciting advances possible in the field of active particles and microrobotics through non-traditional microfabrication ,' Shields added, ' but also underscores the value of mentoring undergraduates early in their research careers, which can lead to groundbreaking results .'

The significance of the study is significant, marking a step forward in the design and use of microparticles in practical applications, especially in the fields of medicine and environmental science.

Isabella Humphrey

Update 10 July 2025