In this study, a magnetic spiral microrobot is proposed for tasks such as diagnosis, drug delivery, and minimally invasive surgery. It has a compact structure with a wireless power supply, low voltage, and a long working time. The microrobot is comprised of a spiral outer shell based on the Archimedes screw structure and an O-ring magnet for an actuator. The Archimedes screw structure produces ...

Physical mechanisms that can influence rotation curves of spiral galaxies are discussed. For dark matter studies, possible contributions due to magnetic fields and non-Newtonian gravitational accelerations should be carefully acconted for. We point out that magnetic fields are particularly important in outermost parts of the disk. In the framework of general relativity the physical reason of an...

Spiral-in/out functional magnetic resonance imaging (fMRI) methods acquire one image before the echo time (TE) and a second image after TE during each scan. Weighted combination of the two images provides a time series with reduced susceptibility dropout in frontal and medial temporal regions as well as increased signal-to-noise ratio (SNR) in regions of uniform cortex. In this study, task acti...

In this paper, the possible realization of the electromagnetic (EM) absorber as a thin metasurface is considered. The metasurface is based on establishing a passive surface of electric and magnetic currents using the Huygen’s principle. So, the absorber is named Huygens Absorber (HA). The metasurface can be designed using split meander lines with spiral rings. In this way, both sides of the sub...