Touch is our first sense to develop in the womb. By ten weeks, a fetus responds to a touch on its cheek and starts building a tactile model of its world. Childhood toys are full of shapes, textures, and the haptic truth of the world. Kissing, sucking, eating, clinging, breaking, throwing, crawling, walking, all require our sense of touch to develop to a high level of sophistication. But after childhood, unless afflicted by blindness, our haptic sense becomes dormant and it is almost a definition of sophistication to privilege visual over tactile sensations. This is obvious not just in the hierarchy of our cultural and intellectual institutions but also in the street. Supermarkets have discovered that it is the visual, rather than the feel or taste of produce, which determines their popularity. Design shops are full of chairs that look cool and stylish, but are insanely uncomfortable. Fashionable clothing is designed to look good, but very rarely to feel good. Ditto shoes. The epitome of this trend is lingerie, which, with today's lacy thong fashion, seems to offer only a visual sensation, both for the wearer and their intimate admirer.
In adult life, our direct sense of the world is abstracted to, and mediated by, buttons and switches. Buttons on a keyboard, buttons on a phone, buttons on a car, buttons in the kitchen, and buttons on remote controls. Even these buttons are highly uniform, either being easy-to-clean minimalist affairs or spongy keyboard trampolines. Reassuringly, despite engaging in much work for space exploration, NASA has been unable to replace food with any kind of button.
The button community has not been deterred though and, despite the wealth of touchable things in the world, such as, well, the whole world in fact, they are developing virtual reality (VR) haptics. Touch is a notoriously difficult sense to simulate because it involves a complex mix of many different types of sensation: roughness, elasticity, thermal conductivity, electrical properties, chemical properties, etc. SensAble Technology's PHANTOM, which allows a single point of force feedback to be simulated, is a basic first step toward VR touch. It is the inverse of a pen – it takes information and turns it into a force. The development of this VR technology and other ‘glove'-based approaches is vital to those developing virtual surgery as a technique to allow specialists to perform remote surgical operations all over the world. This is because mechanical feedback is a critical part of the ability to remotely manipulate objects such as scalpels. Museums also want the technology to allow the virtual handling of rare and delicate objects. Of course, if VR touch technology follows the pattern of the Internet, its expansion will almost certainly not be driven by these worthy aims but by the pornography industry's desire to offer the virtual touching of a different kind of rare and delicate object.
The haptic design of new materials and the development of VR touch require a fundamental understanding of the science of materials, as well as an understanding of the human sense of touch. Thus, interdisciplinary teams are the norm, as discussed in Mike Ashby and Kara Johnson's book, Materials and Design(Butterworth Heinemann, Oxford, 2002). The first international workshop on Materials and Sensations was held in 2004 in Pau, France, and featured physicists, psychologists, materials scientists, designers, and representatives from the fashion and cosmetics industries (www.2psm.fr). This year the Victoria and Albert museum in London is putting on Touch Me (www.vam.ac.uk/exhibitions/future_exhibs/index.html), an exhibition that will explore the pleasures, sensations, and future of touch. It promises to exhibit the history and future of tactile objects.
Scientific talks given without visual aids are in the extreme minority, and most scientists instinctively reach for a piece of paper to explain their point. Songs about our materials science are not handed down to each new generation of scientists, because we don't have any songs about the structure-property relationship, or anything else for that matter. Likewise, the idea of presenting data as a feeling, perhaps in the form of an object, is also nonexistent in the sciences. Yet, for many complex datasets, this may be a far superior way to promote understanding, especially of forces and complex geometries. Architects and sculptors have been doing this for years, of course. Perhaps it is time for materials scientists to trust their feelings a touch more when communicating our discoveries. Publication needn't be the only fruit of research.