Application of electrorheological fluids for vibrotactile transmission tuning: an experimental evaluation

Abstract The growing demand for localized haptic feedback in large-area interactive displays has created a need for compact and controllable vibration modules capable of spatially confined actuation. However, realizing such localization remains challenging because vibrations generated by a single actuator typically propagate throughout the entire structure, leading to diffuse tactile feedback and complex control requirements. This study presents an Electrorheological Tunable Vibration Module (ERTVM) that uniquely enables field-controlled vibration modulation and confinement through the integration of an electrorheological fluid (ERF) layer with a dual-embedded spring (DES) structure. The DES provides mechanical compliance while amplifying the relative stiffness contrast induced by the ERF’s field-dependent rheology, thereby allowing continuous tuning of vibration transmissibility. Systematic experiments demonstrated that ERF activation increased stiffness by about 63% and reduced damping by about 49%, producing a twofold increase in vibration intensity. The module exhibited rapid dynamic response (rise and decay times ≈ 20 ms) and high-fidelity transmission of aperiodic vibration waveforms. When two modules were coupled, spatial vibration localization was achieved, showing average intensity variation (12%), comparable to reported human tactile Just Noticeable Difference (JND) threshold and up to 30% at specific contact points. These results establish the ERTVM as a compact, energy-efficient platform for spatiotemporal haptic displays, offering a scalable route toward multi-point tactile rendering, adaptive automotive touch panels, and large-area interactive surfaces.