Abstract
Multifunctional active materials are indispensable for untethered small-scale (from a few millimeters down to a few micrometers overall size) devices and robots, since they have significant miniaturization limitations on their on-board actuation, powering, sensing, computing, etc. capabilities. In this talk, our recent activities on design and fabrication of new untethered milli/microrobots leveraging various multifunctional materials are reported. Such tiny wireless robots are aimed to be used inside the human body for minimally invasive or non-invasive medical applications. As the first approach, self-propulsion methods are proposed to enable autonomous microswimmers down to a few microns scale. First, self-generated gradients or fields induced by chemical catalytic interactions with the fluidic media are shown to enable self-propulsion for synthetic microswimmers. Next, cell-driven biohybrid microswimmers are presented, where synthetic microswimmer body is propelled by attached biological microorganisms, such as E. colibacteria and microalgae. Such microswimmer swarms are shownin vitroto deliver the loaded cargo (e.g., drug) actively and locally to cancerous tissues, and are fully degraded via exposed NIR light. As the second approach, external light, magnetic or electrical fields, and acoustic waves are used to propel synthetic wireless microrobots. First, light is used to induce propulsion for Janus hollow mesoporous TiO2-Au microparticles in water by photocatalysis. Next, acoustic waves are shown to propel microbubble-integrated microrobots inside fluids. Finally, external magnetic fields are used to propel magnetic tiny robots in various media. Elastomeric magnetic composite materials are proposed to create new untethered soft-bodied millirobots inspired by spermatozoids, caterpillars,and jellyfishes. These soft robots are demonstrated to be able to have seven or more locomotion modalities in a single robot for the first time to be able to move on complex environments, such as inside the human body. A more specialized jellyfish-inspired soft milliswimmer is also demonstrated to realize multiple functionalities by producing diverse fluidic flows around its soft body towards medical applications.
Biography
Metin Sitti received the BSc and MSc degrees in electrical and electronics engineering from Boğaziçi University, Istanbul, Turkey, in 1992 and 1994, respectively, and the PhD degree in electrical engineering from the University of Tokyo, Tokyo, Japan, in 1999. He was a research scientist at University of California at Berkeley, USA during 1999-2002 and a professor in Department of Mechanical Engineering and Robotics Institute at Carnegie Mellon University, USA during 2002-2016. Since 2014, he has been the director of the Physical Intelligence Department at the Max Planck Institute for Intelligent Systems in Stuttgart, Germany. His research interests include small-scale physical intelligence, mobile milli/microrobots, bio-inspiration, advanced soft functional materials, and soft medical robots. He is an IEEE Fellow. He received the Rahmi Koç Science Prize in 2018, SPIE Nanoengineering Pioneer Award in 2011, and NSF CAREER Award in 2005. He received many best paper and video awards in major conferences. He is the editor-in-chief of Progress in Biomedical Engineering and Journal of Micro-Bio Robotics, associate editor in Extreme Mechanics Letters and Biomimetics & Bioinspiration, and an editorial board member in Advanced Material Technologies and Advanced Intelligent Systems journals.