Abstract: A stretchable flexible pressure sensor includes stretchable conductive interconnects, or electrodes, sandwiching an elastic substrate that is stretchable in one or more directions. The interconnects are positioned on opposing surfaces of the elastic substrate and overlap at select sensing areas. The elastic substrate at each sensing area is replaced with a foam or air gap to enable movement of a top stretchable conductive interconnect, a bottom stretchable conductive interconnect or both toward each other in response to an applied force. The stretchable conductive interconnects are each patterned having a meandering shape and are aligned with each other. The meandering shape provides slack such that as the elastic substrate is stretched the slack is taken up.

Abstract: A 3D printing system includes a 3D printer configured to receive as input a coated or un-coated optical fiber, to coat the optical fiber in the case of an input un-coated optical fiber, to treat an outer coating of the coated optical fiber, and to precisely output the coated optical fiber onto a specific location on a substrate such that the coated optical fiber is securely attached to the substrate via the treated outer coating. The 3D printer has a nozzle head that includes treating element for treating, such as heating or curing, the outer coating of the coated optical fiber. The 3D printer also includes a movement mechanism, such as an XYZ gantry, coupled to the nozzle head such that the nozzle head can be precisely moved relative to the substrate for well controlled placement of the treated coated optical fiber on the substrate.

Abstract: A rip stop material is attached at a stress area of a flexible circuit board in order to strengthen the flexible circuit board and minimize ripping and cracking in the polyimide and/or the copper conductors of the circuit. A rip stop transition layer is formed and deposited at a location on the flexible circuit in order to minimize, reduce, if not preventing cracking and ripping of the circuit as it is bent and flexed. The rip stop transition layer can be placed at different locations on and within the flexible circuit in order to minimize cracking and ripping as the flexible circuit is bent, flexed and twisted.

Abstract: A process of constructing a filled via of a printed circuit board comprises drilling a via hole through a body of the printed circuit board, desmearing a barrel of the via hole, metallizing a outer surface of the via barrel, electroplating the via barrel, pushing nano-copper solder into the via hole and heating the circuit board in order to melt the nano-copper solder within the via hole. The nano-copper solder improves the thermal conductivity of the printed circuit board for applications when heat needs to be conducted from one side of the printed circuit board to another.

Abstract: In order to limit the stress and strain applied to a printed circuit board while still maintaining flexibility, a flexible section of the printed circuit board is configured to have a non-linear portion that functions as a hinge when the flexible section is bent, flexed, twisted or otherwise subjected to a motion related force. The hinge configuration improves durability and flexibility while minimizing ripping and cracking of the printed circuit board, particularly interconnects within the flexible section and a transition region between the flexible section and a rigid section of the printed circuit board. The hinge is configured to have a non-linear shape, such as a serpentine or circuitous path that can include curved portions, different linear portions or some combination of curved and linear portions.

Abstract: A flexible circuit board includes a center “rigid” section, such as a printed circuit stack, and an adjoining flexible multi-layer body that are fabricated from a common interconnect layer. A transition material is included at the interface between the center rigid section and the flexible multi-layer body to minimize ripping and cracking of the interconnect layer. The transition material can also be added at stress areas not related to the interface. The transition material is attached at the interface and stress areas of the flexible circuit board in order to strengthen the flexible circuit board in general and in particular the transition material included therein. The transition material layer is formed and deposited at one or more locations on or within the flexible circuit board in order to minimize, reduce, if not prevent cracking and ripping of the flexible circuit board as it is bent, flexed and/or twisted.

Abstract: A stress and/or strain indicator comprises a wearable body, one or more flexible sections, one or more rigid sections and one or more strain gauges. The one or more strain gauges detect a level of stress and/or strain applied to the wearable body in order to indicate when the product is in danger of failing. A warning is activated based upon the level of stress and/or strain applied to the wearable body. For example, the stress and/or strain indicator is able to display a visual and/or an audible warning that a high level of stress and/or strain has been applied to the wearable body and the product is in danger of failing. In some embodiments, the stress and/or strain incident is recorded and downloadable. Consequently, a user is better informed as to when the electronic product is in danger of failing because of damage or misuse.

Abstract: In order to limit the stress and strain applied to a printed circuit board while still maintaining flexibility, multiple small rigid mesas are formed on a flexible printed circuit, where the rigid mesas are physically isolated by trenches formed around their perimeters. Individual electronic components are attached to the multiple rigid mesas. These trenches form openings at which the printed circuit board is enabled to flex, bend or twist, thereby minimizing, if not eliminating, resulting stress applied to the interconnection between the electronic components and the rigid mesas.

Abstract: A circuit board comprises one or more rigid sections, one or more flexible sections, and one or more transition areas where the circuit board transitions from the rigid section to the flexible section. One or more mechanically restrictive components are applied at a transition area to prevent failure and/or breakage of the circuit as it is bent and flexed. The mechanically restrictive components can be dispersed throughout the circuit as a coverlay, an underlay, and symmetrically positioned within the circuit board as an overlay and an underlay.

Abstract: Mechanical measures strengthen a flexible circuit board or deformable electronic by manipulating the location and/or intensity of the stress concentration or to limit bending, torsion, and stretching. A material layer is patterned onto the flexible circuit board with a specific pattern and place of deposition in order to modify the stress concentration and profile of the circuit board and increase its overall strength. The material layer may be configured to modify the stress concentrations during bending away from the weak points in the assembly or to spread the stress during bending by increasing the radius of the bend curvature and therefore decreasing the chance of mechanical failure.