Researchers at the University of Bristol have made a breakthrough in the development of "life-like" synthetic materials which are able to move by themselves like worms.
Scientists have been investigating a new class of materials called 'active matter', which could be used for various applications from drug delivery to self-healing materials.
Compared to inanimate matter – the sort of motionless materials we come across in our lives every day such as plastic and wood – active matter can show fascinating life-like behaviour.
These materials are made of elements which are driven out of equilibrium by internal energy sources, allowing them to move independently.
Researchers from the University of Bristol, in collaboration with scientists in Paris and Leiden, carried out the experiment using special micron-sized (one millionth of a meter) particles called Janus colloids, which were suspended in a liquid mixture.
The team then made the material active by applying a strong electric field and observed the effects using a special kind of microscope which takes three-dimensional images.
Previous research in this field had used larger colloid particles – but by scaling the colloids to a third of their size the University of Bristol researchers were able to experiment in three-dimensions and found fascinating results.
When the electric field was turned on, the scattered colloid particles would merge together to form worm-like structures – which creates a fully three-dimensional synthetic active matter system.
The research paper, ' Traveling Strings of Active Dipolar Colloids' has been published in Physical Review Letters . First author Mr Xichen Chao explained: "We found the formation of fascinating new structures – self-driven active filaments that are reminiscent of living worms. We were then able to develop a theoretical framework which enabled us to predict and control the motion of the synthetic worms solely based on their lengths."
Co-author Prof Tannie Liverpool added: "While applications in the real world are probably far in the future, because these materials can move independently it could eventually lead to the ability to design devices that independently move different parts of themselves, or the design of swarms of particles which can search for a target which could have health applications by having specifically targeted medicines and treatments."
The synthetic worm chains discovered emerge under low-density conditions. At higher densities, the researchers found the particles formed sheet-like and maze-like structures.
The University of Bristol academics believe there may be several useful applications for the breakthrough, which they are investigating now with more experiments and theoretical modelling.
