The presentation discusses a new concept and a paradigm shift in biological, chemical and
explosive sensor system design and deployment. From large, heavy, centralized and expensive
systems to distributed wireless sensor networks utilizing miniature platforms (nodes) that are
lightweight, low cost and wirelessly connected. These new systems are possible due to the
emergence and convergence of new innovative radio, imaging, networking and sensor
Miniature integrated radio-sensor networks, is a technology whose time has come. These
network systems are based on large numbers of distributed low cost and short-range wireless
platforms that sense and process their environment and communicate data thru a network to a
command center. The recent emergence of chemical and explosive sensor technology based
on silicon nanostructures, coupled with the fast evolution of low-cost CMOS imagers, low power
DSP engines and integrated radio chips, has created an opportunity to realize the vision of
autonomous wireless networks. These threat detection networks will perform sophisticated
analysis at the sensor node and convey alarm information up the command chain. Sensor
networks of this type are expected to revolutionize the ability to detect and locate biological,
chemical, or explosive threats. The ability to distribute large numbers of low-cost sensors over
large areas enables these devices to be close to the targeted threats and therefore improve
detection efficiencies and enable rapid counter responses. These sensor networks will be used
for homeland security, shipping container monitoring, and other applications such as laboratory
medical analysis, drug discovery, automotive, environmental and/or in-vivo monitoring.
Avaak’s system concept is to image a chromatic biological, chemical and/or explosive sensor
utilizing a digital imager, analyze the images and distribute alarm or image data wirelessly
through the network. All the imaging, processing and communications would take place within
the miniature, low cost distributed sensor platforms.
This concept however presents a significant challenge due to a combination and convergence
of required new technologies, as mentioned above.
Passive biological and chemical sensors with very high sensitivity and which require no
assaying are in development using a technique to optically and chemically encode silicon
wafers with tailored nanostructures. The silicon wafer is patterned with nano-structures
designed to change colors ad patterns when exposed to the target analytes (TICs, TIMs, VOC).
A small video camera detects the color and pattern changes on the sensor. To determine if an
alarm condition is present, an on board DSP processor, using specialized image processing
algorithms and statistical analysis, determines if color gradient changes occurred on the sensor
array. These sensors can detect several agents simultaneously. This system is currently under
development by Avaak, with funding from DARPA through an SBIR grant.