Electroadhesion (EA) has potential in robotics, automation, space missions, textiles, and tactile displays, but its physics remains underexplored due to limited models and experimental data. This thesis develops an electro-mechanical model to estimate electrostatic forces between human finger and touchscreen under EA and compares it to experimentally measured friction forces. The model aligns well with the data, showing that the electrostatic force changes mainly due to charge leakage from the Stratum Corneum at frequencies below 250 Hz and its electrical properties above 250 Hz. Additionally, a novel approach using electrical impedance measurements estimates electrostatic forces by subtracting skin and touchscreen impedances from the total impedance. This method is the first to experimentally estimate the average air gap between finger and voltage-induced capacitive touchscreen. The effect of electrode polarization impedance, particularly at low frequencies, was also studied, revealing its role in the charge leakage phenomenon. Tactile perception via EA was investigated using DC and AC voltage signals on a touchscreen with 10 participants of varying finger moisture levels. Results showed that AC voltage detection thresholds were significantly lower than for DC, explained by charge leakage at lower frequencies. Participants with moist fingers exhibited higher threshold levels, supported by impedance measurements. The thesis also investigated how touchscreen top coatings influence tactile perception, focusing on EA-free interactions. Psychophysical experiments and physical measurements demonstrated that coating materials significantly affect tactile perception, likely due to molecular interactions. These findings offer insights into finger-touchscreen interactions under EA and have potential applications in designing robotic systems and haptic interfaces using this technology.

翻译：电粘附（EA）技术在机器人学、自动化、空间任务、纺织品和触觉显示等领域具有应用潜力，但由于现有模型和实验数据有限，其物理机制尚未得到充分探索。本研究建立了一个机电模型，用于估算电粘附作用下人体手指与触摸屏之间的静电力，并将其与实验测量的摩擦力进行比较。模型与实验数据吻合良好，表明静电力变化主要源于250 Hz以下频率时角质层的电荷泄漏，以及250 Hz以上频率时其电学特性的影响。此外，本研究提出了一种利用电阻抗测量估算静电力的新方法，通过从总阻抗中扣除皮肤和触摸屏的阻抗来实现。该方法是首个通过实验估算手指与电压感应电容式触摸屏之间平均气隙厚度的技术。研究还探讨了电极极化阻抗（尤其在低频条件下）的影响，揭示了其在电荷泄漏现象中的作用。通过在触摸屏上施加直流与交流电压信号，并招募10名具有不同手指湿润度的参与者，本研究对电粘附触觉感知进行了实验。结果表明，交流电压的感知阈值显著低于直流电压，这可用低频下的电荷泄漏现象解释。手指湿润的参与者表现出更高的感知阈值，该结果得到了阻抗测量的支持。本研究还探究了触摸屏表面涂层对触觉感知的影响，重点关注非电粘附条件下的交互作用。心理物理学实验与物理测量均表明，涂层材料会显著影响触觉感知，这很可能源于分子层面的相互作用。这些发现为理解电粘附条件下手指与触摸屏的交互机制提供了新见解，并对基于该技术的机器人系统与触觉界面的设计具有潜在应用价值。