Electromagnetic Model of Linear Resonant Actuators

Linear resonant actuators (LRAs) are used extensively in consumer electronic devices such as cell phones and fitness trackers to provide haptic signals to users. This work presents a dynamic model of LRAs based, principally, on the electromagnetic aspects of the these devices. The model predicts that the natural frequency exhibited by an LRA can deviate significantly from that predicted by conventional spring-mass-damper dynamic models. Preliminary experimental results appear to support theoretical findings.