Investigating the minimum perceived linewidth of electroadhesion devices

Electroadhesion devices render shape perception on the flat surface by reconstructing friction based on the finger position. The positioning sensor with a low sampling rate limits rendering because of the discontinuous friction caused by fast finger sliding. The positioning sensor with a higher sampling rate needs to be designed to meet the high-fidelity rendering at fast movement. However, a sensor with a high sampling rate that exceeds the range of human perception is also unnecessary because this will increase the burden of the hardware and software. Thus, it is importance to determine the upper limit of the sampling rate required for electroadhesion devices. The minimum perceived width and sliding velocity together determine the maximum sampling rate. This paper uses the line with varying widths to study the minimum perceived linewidth. The minimum perceived linewidths and influencing factors were studied by psychophysical experiments under 16 conditions of four driving voltages and four sliding velocities. The results showed that minimum perceived linewidths were in the micron scale, and the averages were 5.00–53.75 μm. The minimum perceived linewidths were significantly affected by voltages and velocities, especially at low voltages and fast velocities. The minimum perceived width and influencing factors guide the future electroadhesion application. •We proposed a design to maintain finger moving velocity constant and obtain 10μm smallest linewidth with four different velocities.•We measured minimum perceived linewidths by electroadhesion for the first time and determined dual effects of driving voltage and moving velocity.•We found that the averages of minimum perceived linewidths increased with increasing velocities at low voltages.