Fig. 6: Wavelength responses of the mechano-sensor to weak environmental stimuli and obstacle detection.

a Schematic illustration of breeze blowing and water drop dripping on the mechano-sensor micro-hair in the φ = 180° direction. b Responses of the mechano-sensor to breezes in the φ = 180° and 0° directions. c Response of the mechano-sensor as a water droplet is dripped on the micro-hair in the φ = 180° direction. d Photograph of the quadruped cat robot equipped with the mechano-sensor system. e Responses of the mechano-sensor in stationary, standing, and moving states. f Responses of the mechano-sensor when hitting an obstacle while advancing (φ = 180°) and retreating (φ = 0°). g Wavelength shifts of the mechano-sensor caused by various actions, including remaining stationary, stepping forward, squatting down and getting up, hitting an obstacle at φ = 180° and 0°, turning right, and stepping back. The background areas in gray, orange, yellow, green, blue, pink, and purple represent the mechano-sensor response when remaining stationary, stepping forward, squatting down and getting up, hitting an obstacle at φ = 180°, hitting an obstacle at φ = 0°, turning right, and stepping back, respectively.