US 12,000,740 B2
Sensor apparatus
Yunqi Cao, Pasadena, CA (US); Nelson Sepulveda-Alancastro, Haslett, MI (US); and Henry D'Souza, East Lansing, MI (US)
Assigned to Board of Trustees of Michigan State University, East Lansing, MI (US)
Filed by Board of Trustees of Michigan State University, East Lansing, MI (US)
Filed on Nov. 16, 2021, as Appl. No. 17/527,478.
Claims priority of provisional application 63/114,578, filed on Nov. 17, 2020.
Prior Publication US 2022/0155160 A1, May 19, 2022
Int. Cl. G01L 1/16 (2006.01); G01L 5/00 (2006.01); G01N 3/06 (2006.01)
CPC G01L 1/16 (2013.01) [G01L 5/0052 (2013.01); G01N 3/066 (2013.01)] 32 Claims
OG exemplary drawing
 
1. A sensor apparatus comprising:
(a) an elongated workpiece having an exterior sidewall surface;
(b) at least a first pair of flexible piezoelectric sensors attached to opposite sides of the exterior surface of the workpiece, wherein:
each sensor of the first pair of flexible piezoelectric sensors is configured to experience a same type of stress in both direction and magnitude; and
the first pair of flexile piezoelectric sensors being electrically connected to a first electrical terminal;
(c) at least a second pair of flexible piezoelectric sensors attached to opposite sides of the exterior surface of the workpiece, all of the sensors being peripherally spaced apart from each other, wherein:
each of the second pair of flexible piezoelectric sensors is configured to experience a same type of stress in both direction and magnitude; and
the second pair of flexile piezoelectric sensors being electrically connected to a second electrical terminal;
(d) one of the first pair of the sensors being under compressive stress and another of the first pair of the sensors being under tensile stress when the workpiece bends in the first direction;
(e) one of the second pair of the sensors being under compressive stress and another of the second pair of the sensors being under tensile stress when the workpiece bends in the second direction;
(f) the sensors being configured to detect bending curvature of the workpiece in at least two dimensions by sending voltage output signals from both of the sensors of the first pair and/or both of the sensors of the second pair; and
(g) 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 structural deformation of the workpiece, and (iv) determining whether any structural damage has occurred to the workpiece.