Development of new force sensor using super-multilayer alternating laminated film comprising piezoelectric poly(l-lactic acid) and poly(d-lactic acid) films in the shape of a rectangle with round corners

Abstract

A new super-multilayer alternating laminated film in the shape of a rectangle with round corners has been developed. The super-multilayer film, which comprised piezoelectric poly(l-lactic acid) (PLLA) and poly(d-lactic acid) (PDLA) films, was wound with the number of turns on the order of from 100 to 1000 to form piezoelectric rolls. These piezoelectric rolls could generate an induced voltage of more than 95% of the initial voltage for over 10 s when a constant load was applied. The desired duration and magnitude of the piezoelectric response voltage were realized by adjusting the number of turns of the piezoelectric rolls. Similarly to many other conventional piezoelectrics, the piezoelectric rolls enable instantaneous load-dependent voltage generation and attenuation. The piezoelectric rolls are also lighter than conventional piezoelectric ceramics and can be used as a novel pressure sensor.

Development of an Elastic Piezoelectric Yarn for the Application of a Muscle Patch Sensor

“…The fourth type of physical sensor is based on piezoelectric polymers, including poly­(vinylidenefluoride- co -trifluoroethylene) [P­(VDF-TrFE)], − polyvinylidene difluoride, poly­( l -lactic acid), and poly­( l -lactic acid) and poly­( d -lactic acid) composites . These sensors usually are designed as stretchable sensors for body movement detection or pressure sensors for weight measurement from feet.…”

“…Thus, efforts have been made to increase its stretchability and applicable strain. Reported methods include using fiber-based structures, − , curved film-structure, coil structure, and multilayered films . Among these methods, twisted electrospun [P­(VDF-TrFE)] nanofiber ribbons can provide the largest deformations of up to 740% strain .…”

“…18,19 The fourth type of physical sensor is based on piezoelectric polymers, including poly(vinylidenefluoride-co-trifluoroethylene) [P(VDF-TrFE)], 20−24 polyvinylidene difluoride, 25 poly-(L-lactic acid), 25 and poly(L-lactic acid) and poly(D-lactic acid) composites. 27 These sensors usually are designed as stretchable sensors for body movement detection or pressure sensors for weight measurement from feet. Although the typical elasticity of piezoelectric polymers is several GPa and is the lowest among piezoelectric materials, their elastic modulus still is much higher than human skin or muscle.…”

“…Reported methods include using fiber-based structures, [20][21][22]25 curved film-structure, 23 coil structure, 26 and multilayered films. 27 Among these methods, twisted electrospun [P(VDF-TrFE)] nanofiber ribbons can provide the largest deformations of up to 740% strain. 22 The toughness and strength for large deformation were improved considerably.…”

Application of piezoelectric braided cord to dysphagia-detecting system

“…[5][6][7][8][9][10][11][12] In recent years, the flexibility and light weight of piezoelectric polymers have attracted attention in terms of their application to wearable sensing devices. [13][14][15][16][17][18][19][20][21][22][23][24][25][26] In particular, poly(L-lactic acid) (PLLA) [27][28][29] is a promising material for wearable devices owing to its simple preparation and stable piezoelectricity. [11][12][13][14][15]17,[19][20][21][22][23][24] We previously developed a new piezoelectric sensor, which was fabricated in the shape of a Japanese traditional braided cord known as a "Kumihimo", by weaving piezoelectric PLLA fibers (piezoelectric PLLA braided cord).…”