Figure 1: Design and behaviour of the non-reciprocal active acoustic unit cell.
From: Non-reciprocal and highly nonlinear active acoustic metamaterials
(a) In one orientation (foreground) the cell passes acoustic energy, in the other (background) it blocks it. The cell is composed of the PZM shown in the inset sandwiched between two asymmetric Helmholtz cavities. One cavity is highlighted with dotted lines. The asymmetry is given by different diameters of the cavities openings (d1 and d2). Inset: the PZM has three terminals and is used as both the sensing and driven element simultaneously. (b) Nonlinear electronic circuit driving the PZM.
