Fig. 2: Bioinspired Adaptable Multiplanar mechano-vibrotactileHaptic (BAMH) system.

It comprises the control subsystem and the fingertip interface. a The control subsystem and b its electro-pneumatic diagram. The pressure regulator (green rectangles) defines the stimuli intensity. The pressure sensors (magenta rectangles) monitor the air supply and chamber’s pressures. The signal conditioning circuits (orange rectangles) scale the signals received and sent by the microcontroller. A valve actuation circuit(blue rectangles) generates actuation signals with different duty cycle δ, intensities, and frequencies f, illustrating three representative signals. Each valve is connected to a chamber of c the fingertip interface. The chamber’s internal pressure-force relationship d for steady stimulus and e its performance over time; and for vibrotactile pulse (f = 20 Hz and δ = 5%) stimulus f over time and two flat samples and g for different pipe lengths. Base refers to flat sample 1, day 1, and 60 mm pipe length.