Trends in Micro‐/Nanorobotics: Materials Development, Actuation, Localization, and System Integration for Biomedical Applications

Abstract

Micro‐/nanorobots (m‐bots) have attracted significant interest due to their suitability for applications in biomedical engineering and environmental remediation. Particularly, their applications in in vivo diagnosis and intervention have been the focus of extensive research in recent years with various clinical imaging techniques being applied for localization and tracking. The successful integration of well‐designed m‐bots with surface functionalization, remote actuation systems, and imaging techniques becomes the crucial step toward biomedical applications, especially for the in vivo uses. This review thus addresses four different aspects of biomedical m‐bots: design/fabrication, functionalization, actuation, and localization. The biomedical applications of the m‐bots in diagnosis, sensing, microsurgery, targeted drug/cell delivery, thrombus ablation, and wound healing are reviewed from these viewpoints. The developed biomedical m‐bot systems are comprehensively compared and evaluated based on their characteristics. The current challenges and the directions of future research in this field are summarized.

Biocompatible Nanomotors as Active Diagnostic Imaging Agents for Enhanced Magnetic Resonance Imaging of Tumor Tissues In Vivo

“…Compared to the conventional PTT generated by nanomedicine, the NIR‐driven JMS nanomotors influenced tumor cells in a more active way, motion‐based thermomechanical therapy, which might provide a novel efficient strategy for cancer therapy. [ 26,38 ]…”

“…Besides to the implementation of versatile biomedical functions, the localization of nanomotors in vivo is also crucial for the manipulation and control of nanomotors. [ 38 ] Normally, the localization of nanomotors was realized in aid of multiple imaging techniques, such as fluorescent imaging, MR imaging, ultrasound imaging, positron emission tomography, etc. [ 39 ] Among them, MR imaging exhibited great advantages because it could produce high‐spatially resolved images of deep tissues in an arbitrary 3D plane for non‐invasive and real‐time imaging.…”

“…[ 40–42 ] Therefore, MR imaging would be an effective tool for the imaging and tracking of nanomotors in vivo. [ 25,38 ] Besides, as a powerful diagnosis approach, MR imaging has also been used for the imaging of various diseases clinically. [ 42 ] Thus, we also expect to enhance the MR imaging contrast capability with the active propulsion of nanomotors to improve the diagnosis efficacy.…”

Posture Dynamic Modeling and Stability Analysis of a Magnetic Driven Dual-Spin Spherical Capsule Robot

“…When l = 0, the centroid coincides with the sphere center. According to Equations (11), (14) and (15), the combined external torque acting on the DSCR can be expressed in the résal coordinate system…”

“…The external non-contact driven method of the microrobot include the acoustic field [10], the light field [11], the electric field [12], and the magnetic field [13]. Among all the methods mentioned above, the magnetic field actuation is the most promising one for in vivo applications, due to the advantages of high tissue penetration, good biocompatibility, and precise multi-degree-of-freedom control [14].…”