Fig. 7: Time-varying metabeam for Morse coding.
From: Experimental realization of temporal refraction and reflection in elastic beams
a Experimental demonstration of the fundamental Morse code elements—dash, space, and do—using flexural waves with distinct amplitude levels. The experimental variation remains within ±2.5%; the amplitude difference between a dash and a dot exceeds 30%, while that between a space and a dot is ~15%. b Time profile of the resistance R1(t), used to modulate the beam’s effective stiffness to generate these signals. c Comparison of experimental (purple) and simulated (orange) signals encoding the text “MU''.
