Haptic feedback applications

The same actuator behaves differently once it's inside a product. On a watch it has a few grams to move and a wrist that may be swinging, which the wearables guide works through. In a car it may have to shake a heavy display while the road shakes everything else, and car touchscreens and controls covers that case along with steering wheel and seat warnings.

Haptics matters most where people can't rely on sight or sound, and the accessibility guide looks at alerts, screen reader cues, braille displays, and navigation aids. The essay on designing a tactile language covers how to build a vocabulary of touch patterns people can learn, and Nonlinear Actuators and the Wearable UI Revolution explains the hardware that makes discrete taps practical on the wrist.