Application Note

Hewlett-Packard And Cyrano Sciences Sign Electronic Nose Research Agreement

Hewlett-Packard Co. (HP; Palo Alto, CA), and Cyrano Sciences Inc. (Pasadena, CA; 626-744-1700), have teamed up on a project that could bring inexpensive, portable, and highly reliable chemical sensing technology to both lab and process settings. By merging HP's chemical-mass analyzing technology with Cyrano's "electronic nose" device, the companies are creating a specialized tool for picking airborne chemicals out of gas mixtures. This is key for chemical and biological research, as well as food and environmental monitoring.

The Partnership
HP 4440A Chemical Sensor
Electronic Nose Technology

The Partnership (Back to Top)
Cyrano specializes in electronic nose sensing technology, which uses an array of chemical sensors instead of traditional separations/spectroscopy to pick out airborne chemicals from gas mixtures. Through the partnership, Cyrano's electronic-nose sensor array will be teamed with HP's 4440A chemical sensor, which uses quadrupole mass detection to identify airborne compounds. Financial terms of the deal were not disclosed.

"The HP 4440A chemical sensor is the benchmark against which other sensing technologies are measured," says Steven Sunshine, president and CEO at Cyrano Sciences. "We are confident that HP's extensive product engineering experience and our in-depth knowledge of chemical sensors and innovative technology will be a winning combination."

According to Jeff White, marketing manager at HP's Little Falls Analytical Division (Wilmington, DE), Cyrano's approach to portable, inexpensive, easy-to-use sensors complements HP's instrumentation expertise. "We believe their chip-based sensors will find applications in many different markets," White says, "including the large, and exciting, home market."

HP 4440A Chemical Sensor (Back to Top)
Although HP's 4440A chemical sensor/mass analyzer will hardly make electronic noses more portable or affordable (see below), it will confirm the atomic masses of chemicals and help to obtain data that was not previously available through existing electronic nose technologies. The new combination of the 4440A and the electronic nose will, at least in the near term, be much more likely deployed in process settings than in a consumer application such as a refrigerator.

Hewlett-Packard's 4440A Chemical Sensor/Mass Analyzer obtains data not previously available through electronic noses.

The 4440A uses quadrupole technology as a mass sensor to provide qualitative and quantitative information about sample attributes. HP claims the 4440A is rugged, stable, and reliable in a variety of laboratory environments. It is not affected by moisture, humidity, or other substances that can poison typical solid-state sensors.

Electronic Nose Technology (Back to Top)
Like the complex system of receptors and neurons that "fingerprint" and store electrical signatures to the brain in the human nose, the essentially limitless number of different patterns generated by combinations of unique polymers enables Cyrano Sciences to offer a wide range of odor-detection capabilities from one technology base.

Cyrano's electronic nose does not require advanced sensor design or cleansing between tests.

This broadly tuned array of sensors sets itself apart from other technologies because it offers minimal (currently sub-second) cycle time, can detect multiple odors, and can work in almost any environment without special sample preparation or isolation conditions.

The underlying principle of Cyrano Sciences' electronic nose is simple. An array of sensors, composed of dispersed conductive particles within organic polymers, expands like a sponge when it comes in contact with a vapor, increasing the resistance of the composite. The normalized change in resistance is then transmitted to a processor to identify the type, quantity, and quality of the odor based on the pattern change in the sensor array.

Polymers swell to varying degrees because of their unique responses to different vapors. Regardless of whether an odor results from a complex mixture of chemicals in vapor or from a single chemical, the technology contains enough polymer arrays to yield a distinct electrical fingerprint for each vapor. In the end, the pattern of resistance changes on the array is diagnostic of the vapor, while the amplitude of the patterns indicates the concentration of the vapor.

Applications (Back to Top)
Chemical noses consist of sensor arrays rather than analyte-specific sensors. As such, they have the potential to be much more versatile than dedicated analyzers. Instead of generating a simple signal, the strength of which is proportional to the target gas concentration, chemical noses generate a pattern of signals from several distinct sensors. In theory, analytes will elicit unique pattern responses from the device. This quality makes chemical noses equivalent to human noses in their ability to discriminate many different compounds.

Target markets for the proposed products include chemical and biological research, chemical, food, and pharmaceutical processing, environmental monitoring, as well as medical diagnostics and consumer products.

For example, in chemical, pharmaceutical, and environmental work, a portable tool could detect leaks in pipelines and storage containers, even in the presence of other odors. In laboratories, chemical noses could monitor airborne chemicals and alert workers of unhealthy levels of solvents and reagents. Electronic noses could be used to monitor the chemical components of breath or bodily fluids, but this application is highly regulated and will take years to commercialize.

In the process industries, chemical noses might enable food companies to monitor batch-to-batch consistency by providing a distinct pattern for the target formulation. In the consumer arena, HP and Cyrano are looking at possible uses in refrigerators to detect spoiled foods, or as monitors in microwave ovens to indicate when food is cooked properly.

Cyrano Sciences was founded by Nathan Lewis, Robert Grubbs, and Rodney Goodman, all engineering professors at the California Institute of Technology.

For more information, call 626-744-1700 or e-mail

By Angelo DePalma