Soft microrobots that can intelligently react to their environmental stimuli have significant potential for use in biomedical applications, such as minimally invasive surgery. Recent developments in materials science and nanofabrication technology have revolutionized the field of microrobotics, which is currently merging the world of smart and programmable materials with mechatronics and automation. Smart materials with built-in sensing and motion functions have contributed to this new wave of robotics as they have allowed the construction of intelligent reconfigurable microrobots that can switch their shapes in response to environmental cues. These smart materials are usually mechanically flexible and exhibit enhanced biocompatibility and biodegradability to microrobots. Additionally, their shape changing capabilities allow microrobots to exhibit adaptive locomotion, which can be advantageous in complex situations, such as going through narrow vasculature constrictions or overcoming physical obstacles. This project will demonstrate the potential of a new technology platform in which flexible electronics and soft microrobotics will merge for non-invasive bio-intelligent medical treatments, thus paving the way for programmable and selectively-activated medical implants, targeted therapies, and smart diagnostics.
Flexible electronics have attracted great attention in the last decades because of its potential for various applications in food science, wearables, smart agriculture, and medicine. The main feature of these devices, generally realized using ultra-thin coatings with specific electronic, mechanical, and biological properties, is to preserve full functionality even when exposed to mechanical strain applied by the physical deformation of the electronic system. These electronics have been realized on multiple substrates ranging from paper-like materials and stretchable garments to polymeric foils. For medical applications, these thin-film electronics, adhering intimately to skin, provide the capability to wirelessly collect and share vital data (i.e. body temperature, blood pressure, etc.), or to detect and diagnose diseases without invasive protocols. The high mechanical endurance of flexible electronics, and the underlying fabrication technology optimized for fragile substrates, enables their integration into arbitrary deformable objects from the macro- to the nanoscale. In parallel, untethered soft microrobots are able to navigate through complex biological micro-environments and remotely perform minimally invasive therapies on-demand or in a self-adaptive mode, such as for targeted drug delivery. The integration of programmable stimuli-sensitive hydrogel materials in microrobotic architectures allows for multiple functional modes ranging from 3D mobility, targeted delivery, and controllable release of different drugs by exhibiting a morphological change in response to external stimuli or indications of disease, such as varying heat or pH values. For real application scenarios, however, some necessary functions including information processing, remote communications, and position tracking, can still not be achieved. Therefore, a promising strategy for advanced diagnostics and therapeutics with minimal off-target effects is to bridge the gap between soft microrobots and electronics. The use of flexible electronics fabricated at low temperatures (below 200°C) allows for their integration with soft materials such as gels and polymers, a key to realizing advanced diagnostic and therapeutic intelligent microrobots.In this joint project, the Multi-Scale Robotics Lab (MSRL) at ETH Zurich (Switzerland) and the Faculty of Science and Technology at the Free University of Bolzano-Bozen (UniBz) (South Tyrol, Italy), in collaboration with the Project-based Learning-center of the Department of Information Technology and Electrical Engineering (D-ITET) at ETH Zurich, will develop programmable soft microrobots with integrated flexible thin-film electronics using advanced fabrication techniques, such as 2D and 3D photolithography. To design and fabricate Flexible Electronics-Integrated (FEI) Micromachines, this project will be strategically divided into three work packages. First, flexible active electronics (transistors, passive components, and circuits) will be realized on the body of soft robots made of stimulus-responsive multi-layered hydrogels. Next, complex origami-inspired multilayered microrobots (>3 layers), responsive to multiple external stimuli, such as temperature, pH, and light, will be further designed to be integrated with thin-film electronics, to achieve wireless data communication between the robot environment and the external world. Finally, in the last work package, the ultimate goal will be to employ biocompatible and biodegradable material stacks for electronic and microrobots to realize transient robotic systems that are functional (from locomotion and electronic point of view) for specific time spans, and then dissolve. These studies will demonstrate the potential of a new technology platform, in which flexible electronics and soft microrobotics will merge for augmented and non-invasive bio-intelligent medical treatments, thus paving the way for programmable and selectively-activated medical implants, targeted therapies, and smart diagnostics.
Last updated:04.06.2022
