NdFeB/PDMS Flexible Electromagnetic Actuator with Vibration and Nonvibration Dual Modes Based on Three-Dimensional Coils

With the development of virtual reality technology, haptic feedback has aroused great interest in addition to visual and auditory simulations. At present, haptic feedback is mostly based on rigid devices, and it is difficult to meet the requirements of comfort. This paper presents a fully flexible electromagnetic actuator with a magnetic membrane suspended above a flexible electromagnetic induction coil supported by a soft architectural layer. A three-dimensional coil with a size of 150 nm × 7 layers is fabricated by physical vapor deposition and photolithography. The actuator allows motion in two modes with vibrational and nonvibrational states, which is realized by varying the type of current applied to test the deformation characteristic of the magnetic membrane. The optimal performance is obtained when the mass ratio of NdFeB in the magnetic membrane is 60 wt % for a membrane thickness of 500 μm. Under such conditions, we can obtain the 651 μm maximum displacement for the AC vibration condition and the 187 μm maximum displacement for the DC nonvibration condition. This flexible electromagnetic actuator has good potential for haptic feedback applications. This flexible electromagnetic actuator can be used for tactile feedback, where the vibrating mode can effectively generate the tactile signal and the nonvibrating mode can effectively control the magnitude of the tactile signal.