RESINS & MORE
Polymers, nanotechnology and the future of packaging
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anotechnology is increasingly being discussed in the national media but there is still confusion about what it actually means. There’s the science fiction vision of nanoscale submarines cruising through our blood streams and the more cynical and widely held view that nanotechnology is simply a fashionable re-branding of chemistry and materials science. The truth is somewhere in-between. The more extreme visions of nanotechnology evangelists probably won’t happen, but there are important new technologies on the horizon that will have a big impact on most industries – and packaging is one of them. In particular, it is through nanotechnology that we’ll see the long-heralded advent of functional and intelligent packaging. Polymer technology and nanotechnology are closely linked. The original popular notions of nanotechnology were inspired by the idea that our existing engineering methods would be scaled down to the nanoscale. Thus, in science fiction we see imaginative reconstructions of atom-scale gears and cogs, and nano-submarines that look much like their macro-scale prototypes. But physics looks different on the nanoscale, and what works in our world won’t necessarily function when it is shrunk. New effects, such as Brownian motion and strong surface forces, and scale-dependent properties of matter, such as the dominance of viscosity in the flow of water on small length-scales, would mean that even if we could make the nano-submarine of popular myth, it simply would not work. On the other hand, defenders of the radical vision of nanotechnology have an apparently unbeatable argument in their favour when they point to the marvellous machines of cell biology; the molecular motors and membrane transporters that underlie the operations of all living things, ourselves included. These are machines that operate with stunning efficiency at the nanoscale – despite what seems to be a very unfriendly environment in which to do engineering. This is because biology takes those features of the nanoworld that seem to be disadvantageous, and turns them to its advantage. It is the combination of Brownian motion and strong surface forces that leads to the powerful principle of self-assembly. The lack of stiffness at the nanoscale and Brownian motion are exploited in the
Nanotechnology is high on the news agenda in the packaging sector. Ahead of his presentation at next month’s FaraPack Briefing on Polymers and Soft Nanotechnology event, Sheffield University’s Dr Richard Jones explains how nanotechnology will affect the industry
extensive use of molecular shape change as an operating principle for things such as molecular motors. And it is this sort of soft nanotechnology that we are beginning to learn how to practice using synthetic polymers. So what concrete benefits could nanotechnology deliver to the packaging industry? When discussing new technologies, people usually concentrate on the entirely new capabilities that these might bring. But it’s often more important to look at the way in which the technology could take existing capabilities and dramatically reduce their cost. This is certainly going to be the most important part of the equation for costsensitive industries such as packaging. Here, the big story is going to be the growing ability to make very low-cost devices that sense their environment and process information. This will arise from the convergence, facilitated by nanotechnology, of two big technology trends. On the one hand, the ‘smart dust’ concept has popularised the notion of a decentralised, peer-to-peer network of sensing devices. Each of these devices is a self-contained package with power source, rudimentary microprocessor, environmental sensors of various kinds, and a communication system; the cost and size should be low enough that these are essentially disposable. Development of these devices has been funded by the US Defense Department, and they are now being manufactured commercially. Here, the processing power and capabilities of a small computer is shrunk down in size to a few millimetres, and in cost to a few dollars. Meanwhile, and very familiar to the packaging industry, is the development of RFID technology. Rather than stripping down and miniaturising a complex technology, as the ‘smart dust’ project is doing, this adds extra functionality to the simplest of passive labelling technologies: the bar code. The intelligence currently embodied in these devices is pretty minimal and limited to selfidentification. But as capabilities such as environmental sensing and peer-to-peer communication are added to RFID, and ‘smart dust’ becomes cheaper and cheaper, the two technologies will essentially converge. Two important enabling technologies for these developments are going to be the use of nanotechnology for sensitive chemical and biological sensors and the development of low-cost processing routes involving a combination of self-assembly and cheap, printing-based patterning techniques for functional materials. Developments in plastic electronics and the selfassembly of photonic structures from block copolymers give us some pointers for the future. It’s clear that polymer science, with its traditional emphases on processing and cost reduction, will play a crucial role in these developments. Ultimately, we can expect to combine the cheapness of traditional plastics-based packaging with the functionality previously associated with expensive semiconductor devices. In this way, nanotechnology will result in the development of new markets and new business processes. Richard Jones’ new book, Soft Machines: nanotechnology and life, is available from OUP at a discount to Faraday Packaging members. He will also speak at the FaraPack Briefing 2004, organised by the Faraday Packaging Partnership and sponsored by British Brand Group and the Institute of Packaging, on 2122 October at York Racecourse, York, UK. For more information contact Pauline King: +44 113 284 0213 or at pauline.king@faradaypackaging.com
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Plastics in Packaging • September 2004