Now in our 13th year of bringing you beautiful imagery from biomedical science every day

Search the archive of over 4000 images

Tiny programmable soft robots controlled by light with many potential applications

22 October 2021

Travelling Light

Sluicing around our circulatory systems, drug molecules eventually end up where they’re needed but they’re also prone to the swirling currents around organs and tissues. The answer may be tiny soft robots, artificial devices designed to swim through pulsing fluids or gently sway molecules to where they need to be. Surrounded by water, this tiny gear (10 million times smaller than a windmill in a sandcastle) spins anticlockwise after a blast of green laser light and clockwise with red light. Different areas on the gear’s blades heat up in the changing wavelengths, producing a turning force by a process known as the Marangoni effect. Elsewhere, researchers use similar tricks of light to steer devices around corners – prototypes for tiny 'freighters' that may one day deliver chemical cargos to specific destinations around the body.

Written by John Ankers

Search The Archive

Submit An Image

Follow on Tumblr

Follow on Instagram

What is BPoD?

BPoD stands for Biomedical Picture of the Day. Managed by the MRC Laboratory of Medical Sciences until Jul 2023, it is now run independently by a dedicated team of scientists and writers. The website aims to engage everyone, young and old, in the wonders of biology, and its influence on medicine. The ever-growing archive of more than 4000 research images documents over a decade of progress. Explore the collection and see what you discover. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.

Read More

BPoD is also available in Catalan at with translations by the University of Valencia.