Integrated Multifunctional Graphene Discs 2D Plasmonic Optical Tweezers for Manipulating Nanoparticles.

Optical tweezers are key tools to trap and manipulate nanoparticles in a non-invasive way, and have been widely used in the biological and medical fields. We present an integrated multifunctional 2D plasmonic optical tweezer consisting of an array of graphene discs and the substrate circuit. The substrate circuit allows us to apply a bias voltage to configure the Fermi energy of graphene discs independently. Our work is based on numerical simulation of the finite element method. Numerical results show that the optical force is generated due to the localized surface plasmonic resonance (LSPR) mode of the graphene discs with Fermi Energy Ef = 0.6 eV under incident intensity I = 1 mW/µm2, which has a very low incident intensity compared to other plasmonic tweezers systems. The optical forces on the nanoparticles can be controlled by modulating the position of LSPR excitation. Controlling the position of LSPR excitation by bias voltage gates to configure the Fermi energy of graphene disks, the nanoparticles can be dynamically transported to arbitrary positions in the 2D plane. Our work is integrated and has multiple functions, which can be applied to trap, transport, sort, and fuse nanoparticles independently. It has potential applications in many fields, such as lab-on-a-chip, nano assembly, enhanced Raman sensing, etc.

Remote vascular interventional surgery robotics: a literature review.

Vascular interventional doctors are exposed to radiation hazards during surgery and endure high work intensity. Remote vascular interventional surgery robotics is a hot research field, in which researchers aim to not only protect the health of interventional doctors, but to also improve surgical accuracy and efficiency. However, the current vascular interventional robots have numerous shortcomings, such as poor haptic feedback, few compatible surgeries and instruments, and cumbersome maintenance and operational procedures. Nevertheless, vascular interventional surgery combined with robotics provides more cutting-edge directions, such as Internet remote surgery combined with 5G network technology and the application of artificial intelligence in surgical procedures. To summarize the developmental status and key technical points of intravascular interventional surgical robotics research, we performed a systematic literature search to retrieve original articles related to remote vascular interventional surgery robotics published up to December 2020. This review, which includes 113 articles published in English, introduces the mechanical and structural characteristics of various aspects of vascular interventional surgical robotics, discusses the current key features of vascular interventional surgical robotics in force sensing, haptic feedback, and control methods, and summarizes current frontiers in autonomous surgery, long-distance robotic telesurgery, and magnetic resonance imaging (MRI)-compatible structures. On the basis of summarizing the current research status of remote vascular interventional surgery robotics, we aim to propose a variety of prospects for future robotic systems.

A Remote-Controlled Robotic System with Safety Protection Strategy Based on Force-Sensing and Bending Feedback for Transcatheter Arterial Chemoembolization.

Transcatheter arterial chemoembolization (TACE) is the common choice of non-open surgery for hepatocellular carcinoma (HCC) now. In this study, a simple TACE robotic system of 4-degree-of-freedom is proposed to get higher accuracy and stability of the surgery operation and reduce X-ray exposure time of the surgeons. The master-slave control strategy is adopted in the robotic system and a customized sigmoid function is designed to optimize the joystick control of the master-slave robotic control system. A force-sensing module is developed to sense the resistance of the guide wire in linear delivery motion and an auxiliary bending feedback method based on constraint pipe with a film sensor is proposed. With two force-sensing methods, the safety strategy of robotic motion with 9 different motion constraint coefficients is given and a human-computer interface is developed. The TACE robot would monitor the value of the force sensor and the analog voltage of the film sensor to adopt the corresponding motion constraint coefficient in every 10 ms. Vascular model experiments were performed to validate the robotic system, and the results showed that the safety strategy could improve the reliability of the operation with immediate speed constraint and avoid potential aggressive delivery.