A method and system for stress engineering of a transparent material can include an imaging system that can visualize a spatial distribution of an internal stress in a transparent material, an actuator system that can induce stress in the transparent material, the actuator system comprising one or more actuator elements, and a feedback system that can communicate with the imaging system and the actuator system, and which can guide an internal stress distribution in the transparent material toward a preferred final state.

A system for assaying forces applied by cells includes an optically transparent substrate comprising a soft material having a Young's modulus within the range of about 3 kPa to about 100 kPa. An array of molecular patterns is disposed on a surface of the optically transparent substrate, the molecular patterns include fluorophore-conjugated patterns adherent to cells. The system includes at least one light source configured to excite the fluorophore-conjugated patterns and an imaging device configured to capture fluorescent light emitted from the fluorophore-conjugated patterns. Dimensional changes in the size of the patterns are used to determine contractile forces imparted by cells located on the patterns.

Systems and methods may provide for determining an amount of physical bend in an electronic device and comparing the amount of physical bend to a threshold. Additionally, a warning may be generated if the amount of physical bend exceeds the threshold. In one example, one or more values representing the amount of physical bend are stored to a nonvolatile memory on the device and retrieved in accordance with one or more of a diagnostic push event or a diagnostic pull event.

Systems and methods may provide for determining an amount of physical bend in an electronic device and comparing the amount of physical bend to a threshold. Additionally, a warning may be generated if the amount of physical bend exceeds the threshold. In one example, one or more values representing the amount of physical bend are stored to a nonvolatile memory on the device and retrieved in accordance with one or more of a diagnostic push event or a diagnostic pull event.

A measuring arrangement for fiber Bragg grating measurement points and particularly a measuring arrangement for two fiber Bragg gratings (FBG), wherein a first measurement point is subjected to tension and a second measurement point is subjected to pressure, or vice versa. The circuit arrangement includes a broadband light source, a first beam splitter, a second beam splitter, a third beam splitter, a fourth beam splitter, a fifth beam splitter, photodiodes and an optical delay element.

A sensor apparatus includes a sensor device (2), for attaching to an outer surface of a compression garment (1), and a controller. The sensor device (2) comprises a first mounting point (70), attached to a first point on the garment (1), and a second mounting point (45), attached to a second point on the garment (1). The sensor device (2) senses displacement between the first (70) and second mounting points (45). The controller processes information representative of the sensed displacement to estimate a pressure exerted by the compression garment (1) on a wearer of the garment (1).

An optical fiber mold device has a first portion that includes a base layer having a longitudinal feature configured to receive an optical fiber. At least one second portion is disposed over the base layer. The second portion has a center wall and front and back end walls. The center wall, the front end wall, and the back end wall form a mold cavity. At least one first hole is disposed in the mold cavity and is configured to allow mold material to enter the mold cavity. At least one second hole in the mold cavity is configured to allow air displaced by the mold material to exit the mold cavity.

An electronic device may have an optical touch sensor that is insensitive to the presence of moisture. The display may present images through a display cover layer. A light source may illuminate an external object such as a user's finger when the object contacts a surface of the display cover layer. This creates scattered light that may be detected by an array of light sensors. A metasurface grating may be used to couple light from the light source into the display cover layer at an angle such that total internal reflection within the display cover layer is sustained across the display cover layer even when the display cover layer is immersed in water or otherwise exposed to moisture. Additional metasurface gratings may be formed on the display cover layer to redirect light propagating within the display cover layer away from edges that might otherwise defeat total internal reflection.

An electronic device may have an optical touch sensor that is insensitive to the presence of moisture. The display may present images through a display cover layer. A light source may illuminate an external object such as a user's finger when the object contacts a surface of the display cover layer. This creates scattered light that may be detected by an array of light sensors. A metasurface grating may be used to couple light from the light source into the display cover layer at an angle such that total internal reflection within the display cover layer is sustained across the display cover layer even when the display cover layer is immersed in water or otherwise exposed to moisture. Additional metasurface gratings may be formed on the display cover layer to redirect light propagating within the display cover layer away from edges that might otherwise defeat total internal reflection.

A sensor device includes: a light-emitting section that outputs light to a first mirror or a second mirror, the second mirror facing the first mirror and being configured to change an orientation with respect to the first mirror; and a light-receiving section that receives reflection light, reflected from the first mirror and the second mirror, of the light outputted from the light-emitting section.