Abstract
Magnetic interference between haptic actuators and sensitive magnetic sensors can present a challenge in compact electronic devices, such as smartphones or wearable devices. While a static high-permeability shield may contain stray magnetic fields from an inactive actuator, it could also impede the magnetic flux during haptic operation, potentially reducing actuator efficiency. Systems and methods can address this by actively controlling the shield's permeability. For example, a shield made from a high-permeability ferromagnetic material can at least partially enclose the haptic actuator. A permeability-modulation circuit and an associated drive coil can be used to selectively drive the shield material into magnetic saturation when the haptic actuator is operational. In this saturated state, the shield's permeability may be reduced, which can render it substantially transparent to the actuator's magnetic field. When the actuator is inactive, the saturation field can be removed, allowing the shield to return to its high-permeability state. This dynamic control can improve haptic performance during active use and the accuracy of nearby sensors.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Chung, Vincent; Fang, Vander; Wang, Jianxun; Lai, Matilda; and Tally, Chuck, "Active Permeability Control of a Magnetic Shield for Haptic Actuators", Technical Disclosure Commons, (April 24, 2026)
https://www.tdcommons.org/dpubs_series/9918