📋 Tender Overview
Researchers at ETH Zurich have developed a technique for manufacturing micrometre-long machines by interlocking multiple materials in a complex way. Such microrobots will one day revolutionise the field of medicine.Robots so tiny that they can manoeuvre through our blood vessels and deliver medications to certain points in the body researchers have been pursuing this goal for years. Now scientists at ETH Zurich have succeeded for the first time in building such micromachines out of metal and plastic in which these two materials are interlocked as closely as links in a chain. This is possible thanks to a new manufacturing technique they have devised.Metals and polymers have different properties and both materials offer certain advantages in building micromachines. Our goal was to benefit from all these properties simultaneously by combining the two explains Carlos Alcntara formerly a doctoral student in Salvador Pans group at the Institute of Robotics and Intelligent Systems and one of the two lead authors of the paper. As a rule micromachines are powered from outside the body using magnetic fields which means they must have magnetic metal parts installed. Polymers in contrast have the advantage that they can be used to construct soft flexible components as well as parts that dissolve inside the body. If medication is embedded in this kind of soluble polymer it is possible to selectively supply active substances to certain points in the body.High-tech production methodUnderpinning the new manufacturing method is the expertise of ETH Professor Salvador Pan. For years he has been working with a high-precision 3D printing technique that produces complex objects on the micrometre level a technique known as 3D lithography. The ETH scientists applied this method to produce a kind of mould or template for their micromachines. These templates have narrow grooves that serve as a negative and can be filled with the chosen materials.Using electrochemical deposition the scientists fill some of the grooves with metal and others with polymers before ultimately dissolving the template away with solvents. Our interdisciplinary group consists of electrical engineers mechanical engineers chemists and materials scientists who all work closely together. That was the key to developing this method says Fabian Landers a doctoral student in Pans group. He is the other lead author of the paper which has been published in the journal Nature Communications.Vehicle with tiny magnetic wheelsAs a proof of principle for making micromachines by interlocking materials the ETH scientists created various miniscule vehicles with plastic chassis and magnetic metal wheels powered by means of a rotating magnetic field. Some of the vehicles can be propelled across a glass surface while others depending on the polymer used can float in liquid or on a liquid surface.The scientists are now planning to refine their two-component micromachines and experiment with other materials. In addition they will attempt to create more complex shapes and machines including some that can fold and unfold themselves. Besides serving as ferries that distribute active substances future applications of micromachines include treating aneurysms bulges in blood vessels or performing other surgical procedures. Another research goal is to make stents tubeshaped vessel supports that unfold themselves and can be positioned at a specific place in the body using magnetic fields.
