Systems and methods of sensing intraocular pressure are described. An example miniaturized intraocular pressure (IOP) monitoring system is provided using a nanophotonics-based implantable IOP sensor with remote optical readout that can be adapted for both patient and research use. A handheld detector optically excites the pressure-sensitive nanophotonic structure of the IOP-sensing implant placed in the anterior chamber and detects the reflected light, whose optical signature changes as a function of IOP. Optical detection eliminates the need for large, complex LC structures and simplifies sensor design. The use of nanophotonic components improves the sensor's resolution and sensitivity, increases optical readout distance, and reduces its size by a factor of 10-30 over previous implants. Its small size and convenient optical readout allows frequent and accurate self-tracking of IOP by patients in home settings.

The rolled photonic fibers presents two codependent, technologically exploitable features for light and color manipulation: regularity on the nanoscale that is superposed with microscale cylindrical symmetry, resulting in wavelength selective scattering of light in a wide range of directions. The bio-inspired photonic fibers combine the spectral filtering capabilities and color brilliance of a planar Bragg stack compounded with a large angular scattering range introduced by the microscale curvature, which also decreases the strong directional chromaticity variation usually associated with flat multilayer reflectors. Transparent and elastic synthetic materials equip the multilayer interference fibers with high reflectance that is dynamically tuned by longitudinal mechanical strain. A two-fold elongation of the elastic fibers results in a shift of reflection peak center wavelength of over 200 nm.

A hollow cylindrical tube having an outer surface coated with one or more inks is provided, each ink encapsulated in capsules that rupture under one or more specific loading conditions to display a visually perceptible color. The tube may be used to determine the load capabilities of the tube, to optimize the tube construction and to determine load magnitudes of windable materials and/or the winding process.

An impact sensor includes a hollow container having a plurality of walls, a first magnetic member attached to one of the plurality of walls, and a second magnetic member magnetically attracted to the first magnetic member. A marking device is disposed on the second magnetic member. When a force applied to the sensor exceeds a first predetermined value, the marking device engages one of the plurality of walls and wherein the marking device marks the one of the plurality of walls.

An optical probe for a gas turbine engine includes a housing. Also included is a plurality of optical fibers, a portion of each of the optical fibers secured to fiber holders. Further included is an optical head disposed within the housing and having channels extending in a longitudinal direction of the optical head, the fiber holders disposed within the channels. Yet further included is a cap disposed within the housing and operatively coupled to the optical head, the plurality of optical fibers extending through the cap. Also included is an inner tube operatively coupled to the cap, the plurality of fibers extending through the inner tube.

Exemplary practice of the present invention provides an air vehicle and at least one interferometric double-path fiber optic sensor connected with the air vehicle. Each fiber optic sensor includes a pair of optical fibers, viz., an optical sensing fiber and an optical reference fiber, in a parallel and propinquus relationship. The paired optical fibers of each fiber optic sensor are attached to the air vehicle either (i) circumferentially around the fuselage or (ii) lengthwise along the fuselage or (iii) span-wise along the wings and across the fuselage, and are configured whereby the sensing fiber is exposed to the atmosphere and the reference fiber is not. Each fiber optic sensor senses atmospheric infrasound but does not sense atmospheric wind noise, which is negated by incoherency associated with design lengthiness of the optical fiber pair. Noise and strain due to temperature, vibration, and propulsion are neutralized via interferometric common mode rejection.

A sensor arrangement using an optical fiber and methodologies for performing an analysis of a subterranean formation, such as a subterranean formation containing a hydrocarbon based fluid. The sensor arrangement may be used to measure one or more physical parameters, such as temperature and/or pressure, at a multiplicity of locations in the subterranean reservoir. The sensor arrangement may comprise a sensor array comprising an elongated outer casing for insertion in the subterranean formation and into a fluid in the subterranean formation. The sensor array may comprise an optical fiber defining an optical path that links one or more temperature sensors and one or more pressure sensors and transports measurement data generated by the temperature and pressure sensors. A data processing system may be connected to the sensor array to receive measurements from the sensor array and to compute one or more values of a property of an extraction installation operating on the subterranean formation.

The rolled photonic fibers presents two codependent, technologically exploitable features for light and color manipulation: regularity on the nanoscale that is superposed with microscale cylindrical symmetry, resulting in wavelength selective scattering of light in a wide range of directions. The bio-inspired photonic fibers combine the spectral filtering capabilities and color brilliance of a planar Bragg stack compounded with a large angular scattering range introduced by the microscale curvature, which also decreases the strong directional chromaticity variation usually associated with flat multilayer reflectors. Transparent and elastic synthetic materials equip the multilayer interference fibers with high reflectance that is dynamically tuned by longitudinal mechanical strain. A two-fold elongation of the elastic fibers results in a shift of reflection peak center wavelength of over 200 nm.

Provided are a material for pressure measurement, including a color forming layer that contains microcapsules A encapsulating an electron-donating colorless dye precursor and microcapsules B not encapsulating an electron-donating colorless dye precursor, in which a volume standard median diameter D50A of the microcapsules A and a volume standard median diameter D50B of the microcapsules B satisfy Equation 1; a material composition for pressure measurement; and a material set for pressure measurement:

D50A<D50BEquation 1.

Systems for screening and health monitoring of materials are provided. The system can include a material embedded with magneto-electric nanoparticles (MENs), a laser configured to direct incident laser light waves at a target area of the material, an optical filter disposed between the laser and the material, and an analyzer configured to detect the laser light reflected from the material.