A piezoelectric substrate attachment structure including a cable-shaped piezoelectric substrate, a press section provided adjacent to the piezoelectric substrate and pressed from an opposite side from the piezoelectric substrate, and a base section provided adjacent to the piezoelectric substrate on an opposite side from the press section. A ratio Eb/Ea of a Young's modulus Eb of the base section to a Young's modulus Ea of the press section being 10.sup.1 or lower.

A piezoelectric wire of the present invention includes a conductive wire 11 and a polymer piezoelectric layer 12 that coats the conductive wire 11. The polymer piezoelectric layer 12 contains a -phase polyvinylidene fluoride-based copolymer, and the conductive wire 11 has a wire diameter of 1.0 mm or less. The -phase polyvinylidene fluoride-based copolymer is preferably at least one selected from a vinylidene fluoride-trifluoroethylene copolymer and a vinylidene fluoride-tetrafluoroethylene copolymer.

Provided is a piezoelectric substrate including: an elongate conductor; and an elongate first piezoelectric material helically wound in one direction around the conductor, in which the first piezoelectric material includes an optically active helical chiral polymer (A), the lengthwise direction of the first piezoelectric material and the principal orientation direction of the helical chiral polymer (A) included in the first piezoelectric material are substantially parallel to each other, and the first piezoelectric material has an orientation degree of F in a range of from 0.5 to less than 1.0, determined from X-ray diffraction measurement by the following Formula (a):

orientation degree F.=(180???)/180?(a)

(in Formula (a), ? represents a half width of a peak derived from orientation).

Sensing an environment by confining a monitored live subject in an enclosure, detecting an effect on a coaxial piezoelectric cable resulting from the monitored live subject, wherein the coaxial piezoelectric cable is located at least proximate to the enclosure, and deriving information about a state of the monitored live subject based on the detected effect.

A method of fabricating a pressure sensor is disclosed. Initially, a first metal is deposited on top of a substrate, and the first metal is patterned accordingly. A PVDF-TrFE nano fiber is then deposited on top of the first metal layer, and the PVDF-TrFE nano fiber is etched. A second metal layer is subsequently deposited on top of the PVDF-TrFE nano fiber, and the second metal layer is etched to form a pressure sensor.

It is disclosed a composite yarn structure (10) comprising: a first element (15) comprising a coaxial flexible bi-component monofilament including a conductive component (20) and a thermoplastic component (30) exhibiting piezoelectric properties, at least a second element (40) twisted around the first element (15), wherein the second element (40) has a lower elasticity with respect to the elasticity of the first element (15) such that, upon elongation of the yarn structure (10) in a first direction, the yarn structure (10) expands in a second direction, whereby the dimensions of the yarn are increased both in first and second directions to generate an additional force on said piezoelectric component of the first element.