Miniaturized Autonomous wireless sensors for the detection of chemical warfare agents – CAMIGAZ

The advent of international terrorism implies to prevent potential attacks, and in particular those using toxic gases, which are among the simplest materials to use (as already seen for instance during the attack of Tokyo's subway in 1995 ).

Some sensors are commercially available to detect warfare gases, however they suffer from some intrinsic defects that reduce significantly their interest in specific kinds of operation. Up to now, there is still a lack of supersensitive and specific autonomous miniature sensors which can communicate their alert message by wireless means.

Based on a recent proof of concept using sensors made of functionalized silicon nanowires (EP2154525), the Camigaz project aims at developing a demonstrator resulting from the nanotechnologies, a real breakthrough when compared to existing technologies for the detection of warfare gases.

The use of silicon nanowires functionalized by selective molecular chemical receptors allows in a transistor configuration the immediate and very selective detection of toxic compounds. That was already shown for the organophosphorus compounds (family of the sarin). Two different functionalizations will be developed within the project in order to obtain a sensor also sensitive to hydrocyanic acid (HCN) and yperite (mustard gas).

These three types of gas appear among the most dangerous ever known. Nonetheless, they are potentially accessible and easy to handle by any terrorist group. During the project two generations of autonomous sensors will be developed. The first will include relatively simple devices with simple alerting functionalities based on visual and sound alarms. This will allow to validate the three types of sensors developed for the three targeted gases.

Tests under gas will be carried out initially on simulants of toxic gases, and then on real gases: one partner can handle HCN, and other tests will be subcontracted to an authorized european agency. The sensitive devices will then be integrated in a demonstrator of a few tens of cm3 with a simple electronics. It will be autonomous in energy and will be able to communicate any alarm by means of a wireless system.

The final wireless sensor will thus be able to alert on the presence of any of the three toxic gases.