Fig. 1. Examples of tactile paving in use: (a) dome and (b) bar patterns. Fig. 2. First prototype version of foot-based interface: (a) Design concept. Inset: Distribution of fast adapting type I (FAI) mechanoreceptors sensitive to vibrotactile stimulation in the foot sole, adapted from [15]. (b) Prototype (back and forth). This prototype was featured in IEEE Spectrum Online [18]. (c) Experimental measurements of the static axial force versus current. Inset: miniature vibrating dc motor. (d) Drive components all connected by cables. June 2020 IEEE Instrumentation & Measurement Magazine 5