The Voyage of Micro/nanorobots inside the Human Body

Abstract

Controllable locomotion enables micron/nanorobots to voyage and perform microsurgeries inside the human body. With the assistance of micro/nanorobots, medical tasks can be fulfilled more efficiently than traditional treatment approaches. The micro/nanorobots have performed various tasks that would not be possible by conventional methods. Moreover, wireless propelling methods bring about a lot of benefits, so that the biomedical field gains a new development opportunity. Because of the continuous efforts made by researchers in the past decade, tremendous achievements have been obtained for micro/nanorobots working in vivo. Inside the human body, the micro/nanorobots hold great potential for various applications including cancer therapy, sensing, gene silencing and thrombolysis. In this paper, we provide an overview on recent wireless micro&nanorobots applied in cells, blood vessels, tissue and eyes. Actuation methods, including acoustic, magnetic, light, chemical and bioenergy, for micro&nanorobots insidethe human body are summarized and specific applications of them are also discussed. Furthermore, challenges such as speed, biocompatibility, controllability still exist. However, we can also foresee promising developments in future. Multifunction, simplified devices and intelligence will be the forthcoming development directions for in body micro&nanorobots.

Medical Imaging Technology for Micro/Nanorobots

“…Gao et al developed a stimuli-responsive theragnostic nanoplatform to guide the encapsulating gold nanorods using X-ray CT imaging technology, achieving tumorous microenvironment-triggered drug release and effective chemo-photothermal synergistic therapy (Figure 6B) [64]. PET and SPECT are both gamma-ray-based imaging techniques, also known as nuclear medicine imaging [65,66]. Nuclear medicine imaging involves injecting radioactive elements into the body and placing multiple detectors outside the body to receive the radiation signals from inside the body.…”

“…Vilela et al [70] marked 12 µm sized tube-shaped micro/nanorobots with 124I and achieved in vivo imaging within 15 min. The limitations of nuclear medicine imaging are slow imaging speed, making it difficult for real-time imaging and tracking navigation, high cost, short half-lives of radioactive isotopes, which PET and SPECT are both gamma-ray-based imaging techniques, also known as nuclear medicine imaging [65,66]. Nuclear medicine imaging involves injecting radioactive elements into the body and placing multiple detectors outside the body to receive the radiation signals from inside the body.…”

Colloidal State Machines as Smart Tracers for Chemical Reactor Analysis

“…[83][84][85][86][87][88][89][90] Microrobots, controlled and navigated by external operators through magnetic, acoustic, light, or chemical fields, can perform targeted drug delivery, [91][92][93] tissue regeneration, [94] disease diagnosis, [95,96] cancer therapy, [97][98][99] and biofilm removal. [100][101][102][103] With higher intelligence, electronic microrobots have the potential to conduct far more complicated tasks than simple microparticles, such as glucose-responsive in vivo insulin control [72] and neural activity monitoring, [77,78] among many others. Combining the dispersibility of microparticles and the complex functionality of electronic devices, these colloidal microrobots have equipped us with a new tool to study the interior of chemical reactors noninvasively.…”