A Convoy of Magnetic Millirobots Transports Endoscopic Instruments for Minimally-Invasive Surgery

A Multimodal Amphibious Robot Driven by Soft Electrohydraulic Flippers

Soft robots are exceptionally suited to exploring complex environments, including amphibious navigations, due to their flexible and adaptive characteristics. However, achieving efficient actuation and multimodal locomotion or transition in amphibious environments for soft robots is challenging. In this paper, we present a multimodal amphibious robot with radial symmetry configuration and 3 different locomotion modes (crawling on land and underwater, swimming in water). The robot consists of 3 soft electrohydraulic flippers, which can be independently or synergistically actuated to rotate or oscillate in both air and water and generate the propulsion for amphibious locomotion. Theoretical analysis and experimental tests have verified the remarkable amphibious actuation performance of the soft electrohydraulic flippers with effective electrode encapsulation process. Optimal actuation frequencies are also obtained for maximizing the efficiency of the robot's movements in different mediums. Based on the 3 powerful soft electrohydraulic flippers with radial symmetry distribution, the robot can smoothly transition from crawling on land to crawling underwater, and swim up from the bottom to the surface of water, without reconfiguration of the robot. This work demonstrates the first amphibious soft robot based on electrohydraulic actuators with multimodal locomotion transition in an amphibious environment and may open up more possibilities for the development of multimodal soft robots.

Magnetic Micro/nanorobots in Cancer Theranostics: From Designed Fabrication to Diverse Applications

Cancer poses a substantial threat and a serious challenge to public human health, driving the promotion of sophisticated technologies for cancer therapy. While conventional chemotherapy has bottlenecks such as low delivery efficiency, strong toxic side effects, and tumor enrichment barriers, magnetic micro/nanorobots (MNRs) emerge as promising therapeutic candidates that provide alternative strategies for cancer therapy. MNR is a kind of human-made machine that is micro- or nanosized, is reasonably designed, and performs command tasks through self-actuated or externally controlled propulsion mechanisms, which can be potentially applied in cancer theranostics. Here, this review first introduces the components that constitute a typical magnetic MNR, including the body part, the driving part, the control part, the function part, and the sensing part. Subsequently, this review elucidates representative fabrication methods to construct magnetic MNRs from top-down approaches to bottom-up approaches, covering injection molding, self-rolling, melt electrospinning writing, deposition, biotemplate method, lithography, assembling, 3D printing, and chemical synthesis. Furthermore, this review focuses on multiple applications of magnetic MNRs facing cancer diagnosis and treatment, encompassing imaging, quantification, drug release, synergy with typical therapies, cell manipulation, and surgical assistance. Then, this review systematically elaborates on the biocompatibility and biosafety of magnetic MNRs. Finally, the challenges faced by magnetic MNRs are discussed alongside future research directions. This review is intended to provide scientific guidance that may improve the comprehension and cognition of cancer theranostics through the platform of magnetic MNRs, promoting and prospering the practical application development of magnetic MNRs.