A vectorial magnetometer utilising a microstructured optical fibre Bragg grating infiltrated by a ferrofluid

Sensing and actuating photonic devices in magnetofluidic microstructured optical fiber Bragg gratings

“…To achieve so a significant amount of effort in the functionalisation of the MOF capillary walls is required. Suitable silanisation or layer formation techniques were utilized for attaining specific wettability properties with respect to the highly viscous ferrofluid used and either allow low friction translation [12] or immobilization [14]. Other processing steps for achieving controlled ferrofluidic length infiltration and immobilization may include, MOF endface sealing or pumping and concatenation utilising other immiscible fluids [14].…”

A ferrofluid infiltrated polymeric microstructured optical fiber sensor for magnetic field measurements

“…Recently, using such an approach, ferrofluids have been infiltrated in a grapefruit-type MOF where a Bragg grating was previously inscribed for developing magnetic fields optical sensors and actuator [3,4]. A vectorial magnetometer utilizing a microstructured optical fiber Bragg grating has been implemented using this technology [5]. Under the application of magnetic field along the fiber axis, the magnetic liquid moves along the Bragg grating length, while inducing significant changes in the parasitic Fabry-Perot spectral notch observed in reflection.…”

Ferrofluid-infiltrated optical fibers for shear-sensing smart pads

“…The magnetic field induces either translation of the ferrofluid along the length of the grating or changes to the magnetoviscosity refractive index in the ferrofluid. We have realized miniaturized 'in-fiber' magnetometers, 7,8 A/C magnetic field modulators, 9 and spectral trimmers 10,11 based on this magnetofluidic MOF design. We exploited this hybrid fusion of ferrofluids and MOF Bragg reflectors to develop smart pads that can precisely and reliably measure shear stress displacement (ranging from hundreds of microns to several millimeters in a single sensing element) in rehabilitation, soft robotics, and bionic exoskeleton applications.…”