Fig. 13.

Advances in MERABs sensors. a Schematic illustration of the structure and working principle. b Photographs of the PB spots on the LA electrochromic array. c Color intensity of the PB spots shown in b as a function of LA concentration. Reproduced with permission [33]. Copyright 2017, MDPI. d, e Schematic illustration of a self-powered biosensor. Reproduced with permission [140]. Copyright 2014, Elsevier. f Schematic image of electrochromic alarm system on contact lens. g Digital photographs of electrochromic contact lens. h Transparent vision on smart contact lens in the safe situation, and color changing in the emergency situation. i Morse code in electrochromic alarming system. By controlling the time duration of color change. Reproduced with permission [34]. Copyright 2020, Elsevier