In much the same way as dogs with their keen sense of smell can be trained to detect odors, electronic devices can be built to perform this same task. “Electronic sensing” technology has applications in quality control, health care, crime and safety, and environmental monitoring. In health care, we are seeing new innovations in technology that may be able to sniff out disease including cancer, colon cancer, diabetes, Crohn’s disease, preeclampsia, and kidney disease.  In many cases there are molecules in the patient’s breath that can be detected with the electronic nose. These new technologies are accurate and provide non-invasive detection of disease.

Some electronic nose applications currently on the market:

• Alpha MOS – food and drink quality control
• Airsense – air quality monitoring
• Odotech – environmental monitoring
• Sensigent – chemical vapor
• Electronic Sensor Technology – security
• The Enose Company – disease screening

Electronic noses include three major parts: a sample delivery system, odor detecting sensors, and pattern recognition system. The most commonly used sensors for electronic noses include liquid or gas chromatography and mass spectrometery.

Chips That Enable Electronic Nose Applications and Devices

Common sensors for key air quality and environmental parameters such as humidity, temperature, volatile organic compounds (VOCs), particulate matter (PM2.5), and CO₂.

There are a variety of chemical and gas sensors with various methods of measurement. Electrochemical sensors are the most common approach, and operate by reacting with the chemical being sensed and producing an electrical signal that is proportional to the chemical concentration.  Some measure voltage while others measure current or resistivity.

Other gas sensors

Additional articles

• Disease and odor: An intriguing relationship
• The Five Senses of Sensors
• Video: Can cancer be detected from your breath?
• 15 Analog, MEMS and Sensor Startups to Watch
• Smart devices: Micro- and nanosensors

Photo source: Teguh Mujiono