An image of the sensor module
An image of the sensor module
[Click to enlarge image]

The results of and future plans for the "Sensor System Development Project to Solve Social Problems," an ongoing national project, were introduced in a seminar at nanomicro biz/Robotech 2013, which took place from July 3 to 5, 2013, in Tokyo.

In the seminar, the development process of a sensor module that can realize a sensor network just by attaching it like an adhesive tape was revealed.

The goal of the project is to develop a flexible sensor module having wireless communication and stand-alone power source functions as well as related technologies. The sensor module is attached to an object like an adhesive tape, collects environment information and wirelessly transmits the data.

The cost of the sensor is about ¥1,000 (approx US$9.91). Because it can be easily installed and has a low cost, a large number of sensors can be used in manufacturing plants, offices, stores, etc.

In the seminar, an announcement was made by the Green Sensor Network Laboratories of NMEMS TRA, which is a technology research association that carries out the project and is engaged in a joint development project with Japan's New Energy and Industrial Technology Development Organization (NEDO).

The sensor module is made by stacking a flexible antenna equipped with a highly integrated MEMS sensor and a flexible power storage/generation device. It measures 2 x 5cm, and its thickness is 1mm at the thickest part. Currently, the Green Sensor Network Laboratories is developing elemental technologies, planning to complete a prototype in March 2014.

The sensor module can include an electric current/magnetic field sensor, dust level sensor, CO2 concentration sensor, VOC (volatile organic compound) concentration sensor and infrared array sensor. The CO2 concentration sensor uses an ionic liquid that absorbs CO2. And the stand-alone power source consists of an organic material-based dye-sensitized photoelectric conversion device capable of generating electricity with indoor light and a capacitor.

Also, the Green Sensor Network Laboratories is now developing a sheet-shaped flexible device made of organic semiconductor nanofiber. It has already achieved about 80% of the aimed power generation capacity of 150μW.

In regard to the wireless communication function, the Green Sensor Network Laboratories is developing a method that realizes a communication distance of about 100m with a low power consumption and enables to measure distance by using spread spectrum technology as a method suited for wireless sensor devices.