Multi-Intensity Graded Virtual Tactile Feedback Based on Microcurrent Stimulation

Tactile feedback is an essential component of virtual reality systems, as it enhances the user’s immersion and engagement in the virtual environment. However, traditional tactile feedback methods, such as vibration mode, suffer from the limitation of a single feedback mode, while mechanical drive type and microfluidic drive mode is complex in structure and difficult to integrate. Moreover, micro-current tactile feedback offers high integration and rich feedback modalities, but it suffers from issues such as insufficient feedback strength recognition accuracy and discomfort caused by prolonged electrical stimulation. To address these challenges, we develop and design a novel multi-intensity electro-tactile feedback system based on microcurrent stimulation and determine the optimal stimulation paradigm of this system by studying key influencing factors such as stimulation signal parameters, electrode arrays, and grounded electrode, introducing biphasic current pulses, and optimizing the ratio of positive to negative current charge. We evaluate the performance of the system through psychophysical experiments on 35 subjects. The results show that the system achieves 93.3% and 81.7% accuracy in recognizing four and five levels of intensity, respectively, while effectively reducing discomfort caused by micro-current stimulation. This system outperforms traditional methods and has the potential to be a versatile tactile feedback device with wide application scenarios.