Fig. 5: Recognition function induced by programmable acoustic field of a 2D array transducer.

a Schematic diagram showing one working model of the F-URSP, in which a 2D-array US probe was used to excite programmable acoustic fields, with key components and aspect ratios labeled. b Photographs of a 2D array transducer. c Schematic diagram showing the US beam steering and focusing with a transducer array by modifying the transmitting amplitude and phase of each element. d Simulated pressure magnitude distribution at the X–Z plane of a “H” pattern. e Simulated 3D acoustic intensity distribution of a “H” pattern emitted by a 2D array transducer. The color bar (d, e) indicates the normalized acoustic pressure. The maximum value is 0.5 MPa. f–h Voltage magnitude distribution imaging results, which were reconstructed via programmable II-shaped (f), H-shaped (g), and V-shaped (h) acoustic field patterns generated by a 2D US array transducer. The maximum output voltage is 1.98 V. The color bar indicates the magnitude distribution (\(20{\log }\frac{{V}_{{{\mbox{o}}}}}{{V}_{{\max }}}\)). Source data are provided as a Source data file.