The device, developed by research groups lead by Professor Takayasu Sakurai, Institute of Industrial Science, and Professor Takao Someya, Graduate School of Engineering, both University of Tokyo, combines a flexible amorphous silicon solar panel, piezoelectric speaker, temperature sensor, and power supply circuit created with organic components in a single flexible, wearable package.
Constant monitoring of health indicators such as heart rate and body temperature is the focus of intense interest. Sensors for such applications need to be flexible and wireless for patient comfort, maintenance-free and not requiring external energy supply, and cheap enough to permit disposable use to ensure hygiene. Conventional sensors based on rigid components are unable to meet these requirements.
The fever alarm armband incorporates several first-ever achievements. It is the first organic circuit able to produce a sound output, and the first to incorporate an organic power supply circuit created entirely with organic transistors. The former enables the device to provide audible information when the flexible thermal sensor detects a pre-set value, while the latter increases the range of operational illumination and permits the device to function under indoor lighting conditions. The device can provide constant monitoring of body temperature without the need to change batteries.
In addition to the current temperature sensing device, the technology could also be adapted to provide audible feedback on body temperature, or combined with other sensors to register moisture, pressure or heart rate.
This paper was presented at the 2015 IEEE International Solid State Circuits Conference, San Francisco, 22nd to 26th February, 2015. The research was carried out with support from the Japan Science and Technology Agency (JST) as part of the JST Exploratory Research for Advanced Technology (ERATO) programme.