The largest organ in the human body is an interface. Every square millimetre of our skin is connected to the nervous system and receives constant feedback through our sense of touch: friction from our clothes, breeze on our face, the press of gravity against our bodies when we lie down. It’s the only sense we can’t switch off. You can wear a blindfold or plug your ears – but you can’t stop feeling.
As technology takes us further into virtual worlds, the sense of touch is being used to help us make sense of surroundings that are “unreal”. In cars, physical controls on dashboards have long since been replaced by screens that allow drivers to operate everything from music to air conditioning. But when barrelling along, you don’t want to spend too long looking at the screen. So Ultrahaptics, a British company, is working on a system to use ultrasound to project sensations onto the hand as it operates the screen, alerting the driver that they have changed track or adjusted the heating.
Medicine is feeling the benefits too. Robotic surgery enables machines to perform operations, controlled by surgeons using joystick-like devices. The advantage is that robots can work through tiny incisions, reducing recovery times. The disadvantage is that surgeons can’t feel what they’re doing. Now the developers of surgical robots are using haptic techniques to allow operators to feel the texture of tissues through the controls. Another welcome application comes courtesy of Imperial College London, where scientists have developed a robotic rectum – a silicone model with components that replicate how tissues and tumours really feel. Now students can develop their senses without the need for human volunteers.•