Investigating Electro-Tactile Stimulation via Phase-Modulated Interference

This project investigates how tactile perception on the skin can be modulated through a novel electro-tactile stimulation technique known as phase-modulated interference stimulation (PMIS). PMIS represents an emerging stimulation approach that combines characteristics of classical electrical stimulation with principles of temporal interference stimulation. Conventional stimulation methods typically employ a single electrode pair, resulting in nerve activation primarily occurring directly beneath the electrodes. In contrast, both temporal interference stimulation and PMIS require at least two electrode pairs (four electrodes), enabling the generation of interference fields within the tissue. As a result, PMIS allows targeted nerve activation at the point of interference rather than directly under the electrodes. This property enables the stimulation focus to be spatially shifted or “steered” without physically repositioning the electrodes. Furthermore, PMIS enables modulation of pulse width and burst-mode stimulation, thereby providing a flexible framework for shaping sensory perception.

The primary objective of this research is to investigate how variations in stimulation parameters influence and differentiate tactile perception. Particular emphasis is placed on the effects of pulse width, number of pulses, carrier frequency, and stimulation frequency. By systematically varying these parameters, the project aims to determine how specific stimulation configurations affect sensory experiences and neural activation patterns.

To address these questions, the study employs a multi-methodological research strategy that integrates experimental, psychophysiological, and theoretical approaches. Practical experimental setups are combined with data-driven analyses and theoretical modelling in order to obtain a comprehensive understanding of the mechanisms underlying PMIS-induced tactile perception. This interdisciplinary methodology enables both the empirical characterization of perceptual effects and the development of theoretical models describing the interaction between stimulation parameters and neural responses.

The relevance of this research lies in its potential to advance the precision and optimization of non-invasive stimulation techniques. The findings may contribute to the development of innovative therapeutic approaches in fields such as rehabilitation, prosthetics, and neuromodulation. More precise control of electro-tactile stimulation could enable the selective activation of targeted nerve regions, thereby improving the effectiveness, specificity, and safety of treatment methods. In addition, the project provides fundamental insights that may also be applicable to related domains, including sensor technology, human–machine interfaces, and virtual reality systems.

Duration: 01/24 – 12/27 
Funding: internal
Contact: Dr. Simon Merz & Prof. Klaus Peter Koch