Microrobots have the potential to revolutionize many aspects of medicine. These untethered, wirelessly controlled and powered devices will make existing therapeutic and diagnostic procedures less invasive and will enable new procedures never before possible. The aim of this review is threefold: first, to provide a comprehensive survey of the technological state of the art in medical microrobots; second, to explore the potential impact of medical microrobots and inspire future research in this field; and third, to provide a collection of valuable information and engineering tools for the design of medical microrobots.

Microrobots have the potential to dramatically change many aspects of medicine by navigating through bodily fluids to perform targeted diagnosis and therapy. Researchers have proposed numerous micro-robotic swimming methods, with the vast majority utilizing magnetic fields to wirelessly power and control the microrobot. In this paper, we compare three promising methods of microrobot swimming (using magnetic fields to rotate helical propellers that mimic bacterial flagella, using magnetic fields to oscillate a magnetic head with a rigidly attached elastic tail, and pulling directly with magnetic field gradients) considering practical hardware limitations in the generation of magnetic fields. We find that helical propellers and elastic tails have very comparable performance, and they generally become more desirable than gradient pulling as size decreases and as distance from the magnetic-field-generation source increases. We provide a discussion of why helical propellers are likely the best overall choice for in vivo applications.

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The success of capsule endoscopy has promoted the development of the next generation of endoluminal surgical devices, and many research groups have proposed robotic capsules with novel functionalities, such as active locomotion and surgical intervention capabilities. Yet, these capsules are still single robotic units with a limited number of components and degrees of freedom. This paper addresses this inherent limitation of single capsule units by introducing the concept of modular robotics for surgical robotics. In the proposed procedure, the modules are ingested and assembled in the stomach cavity. We report on the key technologies of such a system: its self-assembly, actuation, power, and localisation.

Recent observations of telluric and electromagnetic field variations (radioemissions) assocuated with shallow and intermediate depth earthquakes in the South Aegean are presented. A telemetric system, installed on Crete Island, which continuously records the telluric and electromagnetic field variations is described. In the field stations of the system we measure both the telluric variations (using an appropriate electric dipole configuration) and the horizontal electric component of the electromagnetic field in 3 kHz, 10 hKz, 41 MHz and 53 MHz (using tuned and l/2 antennas respectively. Furthermore, a theoretical model is given on the generation and the form of preseismic telluric variations based on the charge dislocation model.