In recent years there has been a seemingly ever-increasing use of the synonymous adjectives 'smart' and 'intelligent' to describe a diverse range of materials, structures, systems and technologies. [1][2][3][4] The origin of this terminology can be dated to the early 1980s when researchers working mainly in the US, and funded predominantly from defence budgets, began to examine the potential of combining advanced materials and sensors with powerful and compact computers to produce futuristic systems able to monitor their operating environment in real time and respond appropriately.
Public awareness of this technology was given an enormous boost by the prominence given to use of 'smart' munitions during the Gulf war. Various articles appearing in popular science journals [5][6][7] and broadsheet newspapers in the months following the successful conclusion of this conflict served to maintain interest and it became fashionable to examine the use of 'smart' technology in industrial applications far removed from those originally envisaged in aerospace and defence. Various dedicated university research groups were formed at around this time (among the first in the UK being the Smart Structures Research Institute at Strathclyde University), often bringing together academics who had been working on 'smart' technologies for several years without realising it! Over the last five years researchers working in most of the major industrial sectors have given at least some thought to how they might apply 'smart' technology, important areas being in transport, building, civil infrastructure, biomedicine, sport and leisure, power generation and oil, gas and petrochemical. Packaging has not been left out of this process, with the prospects for 'intelligent packaging' being assessed most notably by CEST and Pira International in a report prepared in 1992 under DTI funding. 8 Interest in 'smart' packaging has been sustained over the four years since this pioneering study, with the focus of attention gradually shifting from abstract conjecture to practical application. Notwithstanding the attention now being devoted to all things 'smart', the underlying concepts are still only poorly understood in many quarters and the word must warrant some sort of prize for the proportion of times that it is inaccurately applied. This paper presents a systematic definition of 'smart' * This paper was first presented at an Institute of Packaging Seminar entitled Smart, Active and Intelligent -How Packaging is Reacting to Calls for Better Monitoring, Security and Convenience, held at Melton Mowbray,