Towards Functional Mobile Microrobotic Systems

This paper presents our work over the last decade in developing functional microrobotic systems, which include wireless actuation of microrobots to traverse complex surfaces, addition of sensing capabilities, and independent actuation of swarms of microrobots. We will discuss our work on the design, fabrication, and testing of a number of different mobile microrobots that are able to achieve these goals. These microrobots include the microscale magnetorestrictive asymmetric bimorph microrobot ( μ MAB), our first attempt at magnetic actuation in the microscale; the microscale tumbling microrobot ( μ TUM), our microrobot capable of traversing complex surfaces in both wet and dry conditions; and the micro-force sensing magnetic microrobot ( μ FSMM), which is capable of real-time micro-force sensing feedback to the user as well as intuitive wireless actuation. Additionally, we will present our latest results on using local magnetic field actuation for independent control of multiple microrobots in the same workspace for microassembly tasks.

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A two-spacecraft study of Mars induced magnetosphere's response to upstream conditions

10.5194/epsc2020-788 ◽

2020 ◽

Author(s):

Katerina Stergiopoulou ◽

Niklas Edberg ◽

David Andrews ◽

Beatriz Sánchez-Cano

Keyword(s):

Magnetic Field ◽

Solar Wind ◽

Real Time ◽

Dynamic Pressure ◽

Local Magnetic Field ◽

Mars Atmosphere ◽

Solar Wind Magnetic Field ◽

Magnetic Field Magnitude ◽

Induced Field ◽

The Imf

We investigate the effects of the upstream solar wind magnetic field on the Martian induced magnetosphere. This is a two-spacecraft study, for which we use Mars Express (MEX) magnetic field magnitude data from the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) instrument and Interplanetary Magnetic Field (IMF) measurements and solar wind density and velocity from the magnetometer (MAG) and the Solar Wind Ion Analyzer (SWIA) on board Mars Atmosphere and Volatile EvolutioN (MAVEN), from November 2014 to November 2018. Equally temporally spaced echoes appear in MARSIS' ionograms from which the electron cyclotron frequency and eventually the magnitude of the local magnetic field can be calculated. At the same time solar wind magnetic field data and solar wind parameters from MAG and SWIA respectively are utilized, providing the solar wind input to the Martian system. We make real time comparisons of the IMF and the induced magnetic field in the environment of Mars and we test the ratio B(MEX)&#160;/B(MAVEN) &#160;against various parameters such as the solar wind dynamic pressure, velocity, density, Mach number as well as the Martian seasons, latitudes and heliocentric distances. Additionally, we search for disturbances in IMF which then can be traced in the induced field ultimately revealing the response time of the induced magnetosphere to the solar wind behaviour.&#160; MEX and MAVEN measurements combined allow us to investigate the response of the Martian induced magnetosphere to the solar wind magnetic field. Real time comparisons of the IMF and the induced field could help us understand the mechanisms controlling the structure of the Martian induced magnetosphere.&#160;

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Magnetometer-Based Drift Correction During Rest in IMU Arm Motion Tracking

Sensors ◽

10.3390/s19061312 ◽

2019 ◽

Vol 19 (6) ◽

pp. 1312 ◽

Cited By ~ 12

Author(s):

Frieder Wittmann ◽

Olivier Lambercy ◽

Roger Gassert

Keyword(s):

Magnetic Field ◽

Real Time ◽

Video Game ◽

Homogeneous Magnetic Field ◽

Inhomogeneous Magnetic Field ◽

Alternative Methods ◽

Local Magnetic Field ◽

Magnetic Field Direction ◽

Drift Correction ◽

Time Motion

Real-time motion capture of the human arm in the home environment has many usecases, such as video game and therapy applications. The required tracking can be based onoff-the-shelf Inertial Measurement Units (IMUs) with integrated three-axis accelerometers, gyroscopes,and magnetometers. However, this usually requires a homogeneous magnetic field to correctfor orientation drift, which is often not available inside buildings. In this paper, RPMC (RestPose Magnetometer-based drift Correction), a novel method that is robust to long term drift inenvironments with inhomogeneous magnetic fields, is presented. The sensor orientation is estimatedby integrating the angular velocity measured by the gyroscope and correcting drift around the pitchand roll axes with the acceleration information. This commonly leads to short term drift aroundthe gravitational axis. Here, during the calibration phase, the local magnetic field direction for eachsensor, and its orientation relative to the inertial frame, are recorded in a rest pose. It is assumed thatarm movements in free space are exhausting and require regular rest. A set of rules is used to detectwhen the user has returned to the rest pose, to then correct for the drift that has occurred with themagnetometer. Optical validations demonstrated accurate (root mean square error RMS = 6.1), lowlatency (61 ms) tracking of the user’s wrist orientation, in real time, for a full hour of arm movements.The reduction in error relative to three alternative methods implemented for comparison was between82.5% and 90.7% for the same movement and environment. Therefore, the proposed arm trackingmethod allows for the correction of orientation drift in an inhomogeneous magnetic field by exploitingthe user’s need for frequent rest.

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Local magnetic field measurements, fault creep observations and local earthquakes on the San Andreas fault

Open-File Report ◽

10.3133/ofr78809 ◽

1978 ◽

Cited By ~ 2

Author(s):

M.J.S. Johnston ◽

B.E. Smith ◽

Robert Martin Mueller

Keyword(s):

Magnetic Field ◽

San Andreas Fault ◽

Field Measurements ◽

Local Magnetic Field ◽

Fault Creep ◽

Local Earthquakes ◽

San Andreas ◽

Magnetic Field Measurements

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Magnetic Actuation Based Snake-Like Mechanism and Locomotion Driven by Rotating Magnetic Field

IEEE Transactions on Magnetics ◽

10.1109/tmag.2011.2143698 ◽

2011 ◽

Vol 47 (10) ◽

pp. 3244-3247 ◽

Cited By ~ 22

Author(s):

S. H. Kim ◽

S. Hashi ◽

K. Ishiyama

Keyword(s):

Magnetic Field ◽

Rotating Magnetic Field ◽

Magnetic Actuation

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A multi-magneto-inductive sensor array system for real-time magnetic field imaging of ferromagnetic targets

Review of Scientific Instruments ◽

10.1063/5.0039894 ◽

2021 ◽

Vol 92 (3) ◽

pp. 035113

Author(s):

Huan Liu ◽

Changfeng Zhao ◽

Xiaobin Wang ◽

Zehua Wang ◽

Jian Ge ◽

...

Keyword(s):

Magnetic Field ◽

Real Time ◽

Sensor Array ◽

Inductive Sensor ◽

Magnetic Field Imaging ◽

Field Imaging

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Ferro-self-assembly: magnetic and electrochemical adaptation of a multiresponsive zwitterionic metalloamphiphile showing a shape-hysteresis effect

Chemical Science ◽

10.1039/d0sc05249c ◽

2021 ◽

Vol 12 (1) ◽

pp. 270-281

Author(s):

Stefan Bitter ◽

Moritz Schlötter ◽

Markus Schilling ◽

Marina Krumova ◽

Sebastian Polarz ◽

...

Keyword(s):

Magnetic Field ◽

Light Scattering ◽

Dynamic Light Scattering ◽

Real Time ◽

Self Assembly ◽

Hysteresis Effect ◽

The Self ◽

Self Organization ◽

Stimuli Responsive ◽

Optical Birefringence

The self-organization properties of a stimuli responsive amphiphile can be altered by subjecting the paramagnetic oxidized form to a magnetic field of 0.8 T and monitored in real time by coupling optical birefringence with dynamic light scattering.

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