TUCcurrent research
In an article in the renowned journal “Nature Nanotechnology,” researchers from Chemnitz, Dresden and Shenzhen (China) describe how tiny magnetic springs can take medical applications a big step further
Fig. 1: Micro gripper with built-in piconewton spring. The micro gripper opens and closes by changing the strength of a magnetic field. Graphics: TU Chemnitz/Jacob Müller, photos: Fig. 2: “Micropenguin” with piconewton fins swims through a liquid. Graphic: TU Chemnitz/Jacob Müller, photos: The project was funded by the European Research Council (ERC) as part of the European Union’s Horizon 2020 research and innovation program (funding agreements no. 835268 and no. 853609).
The integration of mechanical memory in the form of springs has been a key technology for mechanical devices (e.g. watches) for hundreds of years, achieving extended functionality through complex autonomous movements. Today, the integration of springs with silicon-based microtechnology has revolutionized the world of planar, mass-producible mechatronic devices that benefit us all, e.g. B. through airbag sensors. For biomedicine, which would like to use ever less invasive procedures in the future, the size scale of an individual cell will play an increasingly important role. Tiny moving devices that can safely interact with individual cells will need to reach much smaller dimensions (around tens of micrometers), be manufactured in tailored three-dimensional shapes, and operate at much lower forces on the piconewton scale, such as lifting weights of less than a millionth of a milligram.
Researchers from Chemnitz University of Technology (TUC), the Shenzhen Institute of Advanced Technology of the Chinese Academy of Sciences and the Leibniz Institute for Solid State and Materials Research (IFW) Dresden show in their current publication in the renowned journal “Nature Nanotechnology”, that controllable springs can be integrated into soft three-dimensional structures at any point using confocal photolithographic manufacturing with a precision in the nanometer range. This technique uses a novel magnetically active material in the form of a photoresist impregnated with magnetic nanoparticles. These “picosprings” have remarkably large and adjustable mobility and can be remotely controlled by magnetic fields – even deep within the human body, enabling microrobot joint movements and micromanipulations far beyond the current state of the art.
In addition, the deflection of picosprings can also be used to visually measure forces, such as propulsion or gripping forces, when interacting with other objects, such as cells. The picosprings were used, among other things, to measure the driving force of micromotors and moving cells, such as. B. Sperm used. In the specialist publication that has now been published, these abilities are described using several constructions that contain picosprings at appropriate locations and can carry out various tasks at the cellular level. They can swim, walk, grab and release cells, and accurately measure and exert the tiny forces required to do this. Figures 1 and 2 show two of these novel structures with built-in piconewton springs – a micro-gripper and a micro-penguin, taken from the paper [].
Prof. Dr. Oliver Schmidt, last author and supervisor of this research work as well as scientific director of the TUC MAIN research center, sees this as another important step on the way to viable, soft and intelligent modular microrobotics. “Remotely controlled microdevices that use magnetic fields are a particularly promising technology for non-invasive medical applications – and this now also applies to the mechanics within these remotely controlled microdevices,” says Schmidt.
“The possibility of integrating microscopic built-in springs will also add a new tool to the growing competencies of Chemnitz University of Technology in the field of microelectronic morphogenesis and artificial life,” says Prof. John McCaskill, co-author of the study, member of the MAIN research center and Founding Director of the European Center for Living Technologies. Chemnitz University of Technology recently reported in detail about microelectronic morphogenesis in a press release.
This project was funded by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreements No. 835268 and No. 853609).
Publication: 3D nanofabricated soft microrobots with super-compliant picoforce springs as onboard sensors and actuators, Haifeng Xu, Song Wu, Yuan Liu, Xiaopu Wang, Artem K. Efremov, Lei Wang, John S. McCaskill, Mariana Medina-Sánchez, Oliver G. Schmidt. Nature Nanotechnology (2024).
Further information give Prof. Dr. Oliver G. Schmidt, Scientific Director of the MAIN Research Center and holder of the Professorship of Material Systems in Nanoelectronics at Chemnitz University of Technology, email [email protected], as well as Prof. John S. McCaskill, MAIN Research Center and Fellow of the European Center for Living Technology, Venice, email [email protected].
Mario Steinebach
03.01.2024