New Sensor Sheet Lighter, Softer Than Feather

Jul 26, 2013
Naoki Tanaka, Nikkei Electronics
Takao Someya, professor at the School of Engineering, the University of Tokyo, showing the newly developed sensor sheet
Takao Someya, professor at the School of Engineering, the University of Tokyo, showing the newly developed sensor sheet
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The sensor sheet attached to a hand
The sensor sheet attached to a hand
[ If it clicks, the expanded picture will open ]

A research group led by Takao Someya, professor at the School of Engineering, the University of Tokyo, announced that it has developed a sensor sheet that is lighter and softer than feather.

The mass of the sheet is 3g/m2, which is about 1/27 that of regular paper. Also, it has a thickness of 2μm and can be flexibly bent. Therefore, it can be attached to a curved surface such as of human body.

Because of the light weight and slimness, it does not cause discomfort when attached to human body. And the research group expects that the sensor sheet will be used for medical and healthcare sensors that continuously collect biological information.

In general, sensors and electronic circuits for medical and healthcare applications are made with hard electronic materials such as silicon (Si). However, for components to be directly attached to human skin, etc, parts that use light and soft materials and do not cause discomfort are demanded.

This time, the University of Tokyo established a technology to form an array of organic TFTs on a 1.2μm-thick plastic film substrate and developed a pressure sensor sheet combining the organic TFT array and pressure sensor elements. In 2010, the university developed a 25μm-thick organic TFT array sheet, but, this time, it reduced the thickness of the sheet by more than 90% to 2μm.

Though the group developed the pressure sensor sheet as an application of the organic TFT array sheet, Someya considers that the sheet can realize medical and healthcare sensors capable of measuring biological information such as myoelectric signals, electrocardiogram, body temperature, heart rate, blood pressure, etc.

The latest research was conducted in cooperation with a research group led by Siegfried Bauer, professor at Johannes Kepler University of Linz in Australia. A thesis about the research results will be published in Nature magazine July 25, 2013.