Guest Editorial - Special issue on machine olfaction

This year is the 10th anniversary of the first special issue on machine olfaction of the IEEE SENSORS JOURNAL. During this past decade, the field has grown in a number of exciting directions, including spectroscopic and olfactory receptorbased sensing, computational models of olfactory processing, and mobile and distributed sensing. This second special issue provides a timely update on advances during the past decade (as well as a vantage point from which to evaluate the last 30 years) in the field and, more importantly, the challenges that still lie ahead. It includes invited papers based upon presentations give at the International Symposium on Olfaction and Chemical Sensing (ISOCS) that was held in New York Digital Object Identifier 10.1109/JSEN.2012.2215434 City in 2011 (see www.olfactionsociety.org). To provide a balanced view of the various advances in the field, the special issue is organized into six distinct topic areas: biological sensors, chemical sensors, sensor systems, data processing, and electronic nose applications. The topic area of biological sensors recognises the fact that considerable effort is being directed towards improving the capability of artificial olfactory sensors by exploring more closely the biological system and seeking to mimic it more closely.