A lot of research has been devoted to creating electrical devices that emulate biological sensors, including:

  • Visual: Cameras, color/light intensity sensors
  • Auditory: Microphones, ultrasonic sensors
  • Tactile: Pressure sensors, temperature sensors
  • Balance: Gyroscopes, accelerometers

However, I have yet to find a comprehensive sensor/processing algorithm to detect and interpret odors. Certainly, there are "olfactory" sensors which are dedicated to a specific purpose, such as carbon monoxide detectors, and other hazardous gas detectors. But I have yet to find a general purpose sensor/processing algorithm that can readily detect and interpret odors within the range and resolution of a human nose.

Do such sensors/algorithms exist? If so, what are they and how do they work? If not, what are the primary obstacles to developing them?


1 Answer 1


Odor assessment is usually performed by human sensory analysis using chemosensors:

A chemoreceptor, also known as chemosensor, is a sensory receptor that transduces a chemical signal into an action potential.

Recently I have also heard of a sensor from Honeywell that could potentially be used in smart phones. These sensors are also called electronic noses:

Bio-electronic noses use olfactory receptors - proteins cloned from biological organisms, e.g. humans, that bind to specific odor molecules. One group has developed a bio-electronic nose that mimics the signaling systems used by the human nose to perceive odors at a very high sensitivity: femtomolar concentrations.

The more commonly used sensors for electronic noses include

  • metal–oxide–semiconductor (MOSFET) devices - a transistor used for amplifying or switching electronic signals. This works on the principle that molecules entering the sensor area will be charged either positively or negatively, which should have a direct effect on the electric field inside the MOSFET. Thus, introducing each additional charged particle will directly affect the transistor in a unique way, producing a change in the MOSFET signal that can then be interpreted by pattern recognition computer systems. So essentially each detectable molecule will have its own unique signal for a computer system to interpret.
  • conducting polymers - organic polymers that conduct electricity.
  • polymer composites - similar in use to conducting polymers but formulated of non-conducting polymers with the addition of conducting material such as carbon black.
  • quartz crystal microbalance - a way of measuring mass per unit area by measuring the change in frequency of a quartz crystal resonator. This can be stored in a database and used for future reference.
  • surface acoustic wave (SAW) - a class of microelectromechanical systems (MEMS) which rely on the modulation of surface acoustic waves to sense a physical phenomenon.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.