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Press Release
Development of a Thin and Highly Sensitive Piezoelectric Sensor
Apr 14, 2014


- for a wide range of applications such as detection of drowsy driving or fatigue, and health monitoring of the elderly.-


Sekisui Chemical Co., Ltd (hereinafter called “Sekisui Chemical.” President: Naofumi Negishi) is pleased to announce that the High Performance Plastics Company (President: Keita Kato) of Sekisui Chemical has developed a piezoelectric sensor with multiple features of being highly sensitive, thin, flexible and durable – electrical properties can be maintained -, adopting its original polyolefin foam with super-fine bubbles as one of the materials.

The High Performance Plastics Company will look for more ways to make good use of the sensor for such purposes as monitoring biological signals generated while people are sleeping or driving or peoples’ health with wearable devices equipped with the sensor.



I. Background of the Development

Sekisui Chemical, under its group vision of developing the frontiers of "Creation of Housing/Social Infrastructure" and "Chemical Solutions," provides various plastic products to be used as materials for housing, automobiles and electronics, and in the medical field.

We have also accumulated know-how on polyolefin foam for many years. The polyolefin foam currently provided by us is excellent in thermal insulation, shock absorption, moldability and other properties, which is extensively used as tape substrates and sealing materials for mobile terminals, automotive interior materials, industrial products, housing materials and other things.

Sekisui Chemical has the top share of the highly foaming polyolefin foam market (according to our own estimation), and is promoting the foam overseas, with ten production sites established in the world (Japan, Korea, China, Thailand, the United Kingdom, the Netherlands, Germany, the United States (two production sites) and Australia)


II. Overview of the Thin and Highly Sensitive Piezoelectric Sensor

1. Structure / Function

The developed piezoelectric sensor, consisting of a polyolefin form sheet and aluminum sheets, converts pressure applied on it into an electrical signal.





An electrical signal is displayed when pressure is applied on the sensor.

Structure / Function


Horizontal axis: time. Vertical axis: voltage.

2. Mechanism of the Sensor

When some pressure is applied on the piezoelectric sensor, slight deformation of charged bubbles in polyolefin form leads to the generation of electricity. The generated electricity travels to the aluminum sheets, which appears on a display as an electrical signal.



Mechanism of the Sensor

3. Original Technology and Specifications

Unlike conventional polyolefin foam, this Sekisui Chemical’s designed polyolefin foam with super-fine bubbles makes it possible to permanently keep electricity around the bubbles and to have high durability – electrical properties can be maintained-. 

(1) Specifications




:80℃,  95% RH , 3 months / -20℃, 3 months, Bending test 500 times, High pressure 2MPa




:30mV/N (Sensitivity to a person’s pulse)








:A heartbeat signal, a breathing signal, a snoring signal and a body motion signal are extracted respectively by the filtering method.


(2) Standardized size



The 2x2 cm to 100x100 cm size range is available.

(3) Design characteristics



With great flexibility, free designs can be made.

(4) Versatility



Compared with conventional polymer piezoelectric sensors where relatively costly resin is used, our piezoelectric sensor adopts general-purpose polyolefin resin as one of the main components, which can be applied to many products in a wider range of fields.

4.  Usage Examples

The Sekisui Chemical’s developed piezoelectric sensor can detect even weak pressure on the surface of the body which is generated by hear beats, pulse beats and breathing, because of which, we believe it can be used for monitoring and managing people’s health condition at home or while at the wheel, and as wearable devices.


・Automobile seat for detecting fatigue or drowsy driving


・Health care device for long-term monitoring of bio-signal


・Mat sheet for health monitoring of the elderly


・Wearable sensors


III. What Sekisui Chemical will Do in the Future

We are looking for business partners who will cooperate with us to find new ways to use the sensor and to make efforts to offer enriched health care.

Samples of the thin, highly sensitive piezoelectric sensor are available. We are scheduled to exhibit the sensor at the Automotive Engineering Exposition to be held at PACIFICO Yokohama from May 21 to 23, 2014.

Press Contact

Corporate Communication Department, Public Relations Group
Fax: +81-(0)3-5521-0510 


This press release may contain forward-looking statements. Such forward-looking statements are based on current expectations and beliefs and are subject to a number of factors and uncertainties that could cause actual results to differ materially from those expressed or implied by such statements due to changes in global economic, business, competitive market and regulatory factors.
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