Sensor apparatus

A sensor apparatus comprising:

• (a) a workpiece having an exterior sidewall surface;
• (b) flexible and self-powered sensors attached to opposite sides of the exterior surface of the workpiece, the sensors being peripherally spaced apart from each other;
• (c) one of the sensors being under compressive stress and another of the sensors being under tensile stress when the workpiece bends in a first direction;
• (d) an electrical circuit, the sensors being configured to detect a characteristic associated with bending or impact of the workpiece by sending voltage output signals from the sensors to the electrical circuit;
• and
• (e) a controller configured to receive the output signals from the sensors and automatically perform:
• (i) determining the direction of the bending of the workpiece, (ii) determining a distance of the bending, (iii) determining an impact force, reconstructing a bending curvature based on the characteristic, and (v) determining structural health and/or damage of the workpiece based on the bending curvature.

A sensor apparatus comprising:

• (a) flexible and self-powered sensors located on opposite sides of a longitudinal centerline, and the sensors being spaced apart from each other, wherein the sensors include a pair of sensors and each sensor of the pair of sensors is configured to experience a same type of stress in both direction and magnitude;
• and the pair of sensors being electrically connected to an electrical terminal;
• (b) each of the sensors having a thickness of 0.08-2.0 mm and including overlapping polymeric and metallic layers;
• (c) the sensors being configured to detect a bending or impact characteristic;
• and
• (d) an electrical circuit, comprising gain buffers, connected to the sensors, wherein the buffers pass along the bending or impact characteristics to an on-site electronic component which translates the signals to a real time data array;
• and
• (e) a controller configured to receive the bending or impact characteristics from the sensors and determine a bending curvature and a direction of the bending curvature based on the bending or impact characteristics and a bending algorithm including:
• K(θ)=k/hdrV(θ)
• and θ=arctan(Vy/Vz) where Vθ=√{square root over (Vy2+Vz2)}
• wherein the bending curvature k(θ), with its bending curve θ, Vz measures a bending output of the first pair of sensors, Vy measures a bending output of the second pair of sensors.