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Taatizadeh, Erfan

University of British Columbia

This thesis details the development, simulation, and validation of ultrathin, flexible tri-layer conducting polymer (CP) actuators for tactile feedback. While conventional haptic solutions are often bulky, rigid, or require high operating voltages (e.g. >1 kV in dielectric elastomers), this work focuses on tri-layer CP actuators with Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) electrodes on a central polyvinylidene fluoride (PVDF) membrane to address these limitations. This creates an ultrathin, flexible bending CP actuator designed to indent the finger, offering a compact, low-voltage (< 2 V) haptic solution. To enhance force output and tactile sensation, novel CP actuator geometries were explored with material optimization. A comprehensive physics-based simulation model was developed to guide this optimization, incorporating electrical, electrochemical, and mechanical properties. This analysis resulted in ~140±1 μm thick CP tri-layer actuators with an 8 μm conducting polymer layer, a thickness that provided a good balance of properties for perceptible sensation. This simulation-guided approach led to the proposed Clover and Flower designs, whose triangular-shaped beams taper inwards. This geometry increases stiffness and improves performance over simple rectangular CP actuators. Actuation speed in the tri-layer CP actuators is primarily limited by ionic and electronic resistances. While chemical post-treatments enhance actuation speed, they often reduce the CP actuator's mechanical stiffness, a critical trade-off that diminished tactile perceptibility. These novel CP actuators delivered peak displacements of around 1 mm and blocking forces of approximately 10 mN when driven at low voltages (500 mV). The devices also demonstrated dual-mode functionality, with a piezo-ionic sensing response of ~0.25 mV per mm of deflection. The efficacy of the Clover and Flower designs was confirmed through psychophysical testing on human volunteers. The CP actuators produced perceptible tactile sensations, from pressure to flutter, across a frequency range of 0.1 Hz to over 50 Hz. This integrated approach, combining predictive modeling with empirical and perceptual validation, establishes quantitative design principles for CP actuators and demonstrates their feasibility for responsive haptic systems.

Text

2025-07-14

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/91599

Biomedical Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/