Power generator, fluid sensor, and fluid sensor net

A power generator comprising:

• a stress producing member formed in a columnar shape extending in a direction of a predetermined axis, having an outer circumferential side face that defines a contour of an orthogonal cross section to the predetermined axis rotationally symmetrical around the predetermined axis, and including a piezoelectric module structure comprising a plurality of piezoelectric modules arranged around the predetermined axis in a rotationally symmetrical manner, and producing a stress inside the stress producing member originating from a stress variation produced by a fluid around the stress producing member, the plurality of piezoelectric modules each including a pair of piezoelectric element and electrodes connected to both ends of the piezoelectric element in a polarization direction;
• a suppressing member which is connected to one end of each of the plurality of piezoelectric modules in the polarization direction, and which suppresses a displacement of the stress producing member in order to cause the stress producing member to produce a stress;
• and
• an adder that adds voltages output by the plurality of piezoelectric modules, respectively.