Flexible organic circuit makes fever alarm

February 24, 2015 // By Peter Clarke
Researchers from the University of Tokyo have developed a fever alarm armband, a flexible, self-powered wearable device that includes a temperature sensor and sounds an alarm in case of high body temperature.

The armband, developed by research groups lead by Professor Takayasu Sakurai at the Institute of Industrial Science and Professor Takao Someya at the Graduate School of Engineering, combines a flexible amorphous silicon solar panel, a piezoelectric speaker, temperature sensor, and a power supply circuit created with organic components in a single flexible, wearable package.

The organics circuits are based on CMOS FETs that operate at 12V.


The armband is 30 cm long and 18 cm wide, and can be worn either directly on the skin or on top of clothing. The device is designed so that the thermal sensor is located between the arm and the body. The organic power supply circuit is located under the piezo film speaker to reduce surface area. Source: 2015 Sakurai Lab/Someya Lab.

The armband is for monitoring of health indicators, such as heart rate and body temperature, in infants and the elderly and in patient care. Such sensors need to be light, flexible and wireless for patient comfort and low-cost so they can be disposable for reasons of hygiene. Conventional sensors on rigid printed circuit boards do not meet those objectives the researchers said. The University of Tokyo's flexible solution incorporates organic components that can be inkjet printed on a polymer film.

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