The Sensual Computer: High-Touch, High-Tech

How does your computer feel today? No, we’re not asking about its state of cybernetic health but about whether it’s giving you any tactile feedback or manipulative capability through your fingers. Touch is the latest to be added to the list of human senses a computer can address. It’s called haptics, from the Greek haptesthai, meaning to grasp or touch.

The earliest haptic devices for computers were braille readers. With them, a blind user can move his or her finger along a line of metal pins that form a braille representation of the current on-screen line of text. Although very useful, these devices are limited to rendering text.

There are now a few more devices that use haptic technology. Developed a few years ago, joysticks and similar gaming controls employ force feedback, offering varying resistance to movement, depending on what is happening on-screen.

The newest devices are haptic mice from Logitech Inc. that use a vibration-generating motor to simulate different surface textures and materials. They’re relatively simple and inexpensive, employing new technology from Immersion Corp. More than just a frill or a thrill, “the addition of tactile feedback to computer mice can significantly enhance user performance,” says Jack Dennerlein, assistant professor of ergonomics at Harvard University. “Our laboratory studies show people complete basic cursor-targeting tasks faster with tactile feedback.”

But there are more sophisticated haptic tools available. Perhaps the best-known is the Phantom from SensAble Technologies Inc. This device employs a moving arm that ends in a stylus for the user to hold or a thimble into which the user inserts a finger. These are used in conjunction with FreeForm Modeling System software.

As the user moves the device’s arm, a cursor moves around the screen. Using the device, if one encounters a “solid” object in the on-screen universe, the arm is stopped. Moving along a surface provides tactile information about the surface’s texture, and the user can readily sense curves and corners and, by exerting more pressure, cause deformation of the object.

Using “digital clay” as a sculpting medium, this system essentially does for clay and foam modelling what the word processor did for typing. The process may not be faster for creating the first object, but once that’s captured, it can be manipulated, modified and rescaled digitally. The artist can copy and reuse model features, control hardness and smoothness of the clay, and mirror and scale objects – and “undo” is just a keystroke away.

One application for this technology is in moviemaking, particularly the creation of models. U.K.-based design studio Synapse Modelmaking Ltd. used SensAble’s hardware and software to design characters and figures for the recent animated feature film Chicken Run. Because of the digital nature of the modelling, the studio was able to get nearly instant approval from the production company, Aardman Animations Ltd.

The film company representative “asked if he could make a change to the model,” recalls Synapse director Roger Hulks, “and we implemented the change immediately – right before his eyes.” Synapse got approval for its design on the spot, and the Aardman representative was dazzled. “He still goes on about it today,” says Hulks.