Two-dimensional actuation of a microrobot with a stationary two-pair coil system

Abstract

This paper proposes a new two-dimensional (2D) actuation method for a microrobot that uses a stationary two-pair coil system. The coil system actuates the microrobot by controlling the magnitude and direction of the external magnetic flux. The actuation of the microrobot consists of an alignment to the desired direction and a linear movement of the microrobot by non-contact electromagnetic actuation. Firstly, the actuation mechanism of the stationary coil system is theoretically derived and analyzed. Secondly, the tendency of the magnetic flux in the coil system are analyzed and compared by preliminary theoretical analysis. Through various locomotive experiments of the microrobot, the performance of the electromagnetic actuation by the proposed stationary two-pair coil system is evaluated. Using the proposed 2D actuation method, the microrobot is aligned to the desired direction by Helmholtz coils and is driven to the aligned direction by Maxwell coils. By the successive current control of the coil system, the microrobot can move along a desired path, such as a rectangular-shaped or a diamond-shaped path.

EMA system with gradient and uniform saddle coils for 3D locomotion of microrobot

“…Since a Maxwell coil generates a uniform gradient magnetic near the center of the coil along the x-axis, the Maxwell coil can generate the magnetic force to propel the microrobot located near the center of the coil along the x-axis. The magnetic fields generated by Helmholtz and Maxwell coils were shown in our previous work [6,7].…”

“…Recently, EMA methods of a microrobot in the 2D plane have been studied extensively [3][4][5][6]. However, because a blood vessel in human body is a 3D structure, the microrobot should have 3D locomotion capability.…”

Laminar flow assisted anisotropic bacteria absorption for chemotaxis delivery of bacteria-attached microparticle

“…4 Big Data Institute and Inter-university Semiconductor Research Center, Seoul National University, Seoul 151-744, Republic of Korea.…”

“…Microrobots, however, need suitable microactuators for propulsion and one of the major challenges are sophisticated fabrication or assembly of a proper micro and nanoscale actuator for the microrobot. In the meantime, various types of actuators have been actively investigated considering their reliability, controllability and limited size for their potential applications to these microrobots, such as an electrostatic actuator [3,4] and a piezoelectric actuator [5], etc. While these actuators can provide a fast and controllable movement in precise manner inside human body (low Reynolds number environment in terms of fluid dynamics [6,7]), they either create inherent bubbles due to electrolysis, require continuous onboard power supply or are applicable only in transparent environment.…”

Softening Hard Stool Using Magnetically Controlled Fe3O4 Nanoparticles

“…Chanu and Martel (18) proposed a magnetic resonance imaging (MRI)-system-based method for driving microrods. Yesin et al (19) and Choi et al (20) actuated a ferromagnetic microrobot with Helmholtz and Maxwell coil pairs. Similar to previous biological experiments on the manipulation of micro-and nanostructures, we propose a swaying nanoparticle (NP) aggregate approach to break and soften hard stools by contact.…”