Polymer Compositions with Electronic Sensitivity to Ethylenic Vapors

Unmet Need
Ethylene is a naturally occurring hydrocarbon gas that is odorless and colorless. Naturally, ethylene occurs as a plant hormone and is a marker of fruit ripening. Other ethylenic compounds also include components of industrial emissions and components of breath. Current methods of ethylene detection such as photoacoustic spectroscopy, gas chromatography and electrochemical sensors all have their respective limitations – they are too expensive, bulky, have low sensitivity, or rely on high temperatures in order to function. Though a recent sensor by Swager et. al. was designed to bypass these issues, it failed to successfully address the issue of selectivity. Gasses such as acetonitrile (100 ppm) and acetaldehyde (75 ppm) had much higher responses compared to that of the lower limit (1ppm) of ethylene. There is a need to design a flexible, inexpensive sensor for vapor-phase ethylenic molecules, in particular, ethylene.

Technology Overview
Electronic sensors are generally cheaper and thus, easily scalable. They are monitored with inexpensive equipment and then analyzed and archived by computers. Due to the limited physiochemical reactivity of ethylene, ethylene electronic sensing has always been a challenge for the horticulture industry. Researchers from Johns Hopkins have made progress in addressing this issue. They have designed an electronic sensor for ethylenic compounds by using a particular material to interact with an ethylenic compound so that the impedance of the element changes. In one embodiment, this invention provides an enhanced electronic response in the chemiresistive element to ethylene vapor present with concentrations of as little as 50ppm. The detection of ethylenic compounds can be applied beyond the field of horticulture, and also has varying applications in medical diagnosis.

Stage of Development
A prototype has been developed.

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