An international team of researchers at Johannes Kepler University (JKU) is developing robots from soft materials. A new article in Communications Materials magazine demonstrates how these kinds of soft machines react by using weak magnetic fields to move very quickly. They even manage to quickly grab a fly that has landed on them.
“When we imagine a moving machine such as a robot, we imagine something that is largely made of solid materials,” explains Martin Kaltenbrunner. He and his research team from the JKU Soft Materials Physics Department and the LIT Soft Materials Laboratory are working on a soft material system. The creation of such systems is based on the idea of creating favorable conditions that will maintain close interaction between a robot and a person in the future and without possible physical harm from durable mechanical machines.
Scientists have presented a new approach to electromagnetic motors. Instead of copper wire and iron, elastic materials and liquid metal have become the main ingredients in soft robots. Scientists have also recently introduced a new type of biogel that is resilient, flexible and stable enough to combine with electronic components to create a kind of “soft robot”.
The group, led by Kaltenbrunner and Denis Makarov (Helmholtz Center, Dresden-Rossendorf), is currently taking another step forward in the development of such machines. Two researchers noted that previously the disadvantage was that soft robots could change shape very slowly. Their new idea is based on using flexible polydimethylsiloxane plastic and mixing magnetic microparticles such as an alloy of neodymium, iron and boron.
The researchers gave their little soft robots different shapes. Depending on the shape, placement of microparticles and the thickness of the materials used, robots could move in different ways under the influence of a changing magnetic field in the environment. These actuators are only a few micrometers thick and a few micrograms in weight, so they require little energy to move. In addition, the components can repeat movements millions of times without any modification.
By influencing and altering the magnetic field, Kaltenbrunner and his colleagues were able to build tiny robots that could hover, swim, and – in the broadest sense – even walk. Scientists have also shown that in just a few milliseconds, their flower-shaped robots can catch a fly that lands on them.
Scientists say their development opens up new possibilities for creating soft robots that can move very quickly. The long-term idea is to primarily produce more sophisticated mini-machines that could, for example, help work with the blood vessels in the human body. For this, the materials used must be biodegradable and easily controllable.