In this work, a new design for a 4×2 acoustic priority encoder using fluid-fluid two-dimensional phononic crystal (PnC) ring resonators is presented. The priority encoding operation is enabled by the phononic bandgap characteristics of the mercury-water crystal, which suppress unwanted frequency components while allowing strong confinement and coupling of the resonant mode. At the selected operating frequency of 45.1 kHz, located inside the second bandgap, the ring resonators support constructive interference and selective energy circulation, allowing the highest-priority input to dominate the output logic state. The device structure incorporates two PnC ring cavities and engineered waveguide path lengths to control resonance-based logic discrimination. Performance is validated through high extinction and contrast ratio metrics. The proposed structure provides an acoustically driven alternative for integrated phononic logic circuits, offering potential use in underwater and medical signal-processing applications.
BenchabaneSKhelifARauchJY, et al.Evidence for complete surface wave band gap in a piezoelectric phononic crystal. Phys Rev E: Stat, Nonlinear, Soft Matter Phys2006; 73(6): 065601.
3.
BourquinYWilsonRZhangY, et al.Phononic crystals for shaping fluids. Advanced materials2011; 23(12): 1458–1462.
4.
Rostami-DogolsaraBMoravvej-FarshiMKNazariF. Acoustic add-drop filters based on phononic crystal ring resonators. Phys Rev B2016; 93(1): 014304.
5.
SunJHWuTT. Propagation of acoustic waves in phononic-crystal plates and waveguides using a finite-difference time-domain method. Phys Rev B Condens Matter2007; 76(10): 104304.
6.
LeiLMiaoLLiC, et al.Extending bandgap method of concentric ring locally resonant phononic crystals. Appl Phys A2020; 126: 1–14.
7.
XuZWuFGuoZ. AND and OR logic gates based on a phononic crystal ring resonator cavity. Mod Phys Lett B2016; 30(31): 1650388.
8.
LiuJGuoHWangT. A review of acoustic metamaterials and phononic crystals. Crystals2020; 10(4): 305.
9.
RostamiAKaatuzianHRostami-DogolsaraB. Acoustic 1× 2 demultiplexer based on fluid-fluid phononic crystal ring resonators. J Mol Liq2020; 308: 113144.
10.
IbariasMDoportoJKrokhinAA, et al.Tuning the decay of sound in a viscous metamaterial. Philos Trans A Math Phys Eng Sci2022; 380(2237): 20220007.
11.
YarivAXuYLeeRK, et al.Coupled resonator optical waveguide: a proposal and analysis. Opt Lett1999; 24(11): 711–713.
12.
ChenITLiBLeeS, et al.Optomechanical ring resonator for efficient microwave-optical frequency conversion. Nat Commun2023; 14(1): 7594.
13.
OmraniEMNazariF. Magnetically adjustable AND/XOR logic gates using Terfenol-D in phononic crystal. Sci Rep2025; 15(1): 12169.
RanjbarSNazariFHajizadehR. A magnetically switchable demultiplexer via Terfenol-D in phononic crystal. J Magn Magn Mater2024; 609: 172484.
16.
BinARRakshitJKHossainM, et al.Design of phononic crystal ring resonator-based acoustic 2×1/4×1 multiplexer and 1×2/1×4 demultiplexer. Braz J Phys2024; 54(2): 57.
17.
BinARRakshitJKKumarD, et al.Designing of acoustic half adder and half subtractor using fluid–fluid phononic crystal based ring resonator. Appl Phys A2025; 131(1): 1–12.
18.
BinARYakkalaBRakshitJK, et al.Numerical investigation of 4× 2 encoder and 2× 4 decoder using phononic crystal based ring resonator for acoustic applications. Journal of Vibration Engineering & Technologies2025; 13(1): 29.
19.
BinARRakshitJKKumarD. Design of acoustic 4×2 encoder using phononic crystal based single ring resonator. In 2024 IEEE silchar subsection conference (SILCON 2024). IEEE, 2024.
20.
DasSSinhaNBinAR, et al.Microring assisted mach–zehnder interferometric structure based electro-optic adder for photonic integrated circuits. Opt Quant Electron2023; 55(12): 1119.
21.
ReyesDWalkerEZubovY, et al.All-acoustic signal modulation and logic operation via defect induced cavity effects in phononic crystal coupled-resonator acoustic waveguides. New J Phys2019; 21(11): 113012.
22.
HossainMRakshitJK. Implementation of all-optical synchronous and asynchronous binary up counters using silicon micro-ring resonator. Opt Eng2022; 61(10): 105105.
23.
SinghMPRakshitJKHossainM. Design of polarization conversion and rotation based ternary logic AND/NAND, OR/NOR, Ex-OR/Ex-NOR gates using ring resonator. Opt Quant Electron2021; 53(12): 703.
24.
HossainMMondalKKumarD, et al.Design and study of silicon microring resonator based all-optical binary-coded decimal adder. Opt Quant Electron2023; 55(12): 1100.
25.
RajaAMondalKNagarajuV, et al.2:1 multiplexer based all-optical NOT, AND, OR gates, one-bit half adder and subtractor employing silicon microring resonator. Opt Eng2024; 63(6): 065104.
HuangSWChangYJ. A full parallel priority encoder design used in comparator. In 53rd IEEE international midwest symposium on circuits and systems. IEEE, 2010, pp. 877–880.
28.
RanjbarSNazariFHajizadehR. Magnetically controlled bidirectional 2× 2 elastic switch using Terfenol-D in a phononic crystal-based mach-zehnder interferometer. J Sci Adv Mater Devices2025; 10: 100926.
29.
OmraniEMNazariF. Magnetically tunable 4× 2 encoder utilizing Terfenol-D-embedded phononic crystal ring resonators. J Sci Adv Mater Devices2025; 10(2): 100861.
30.
LiYFHuangXMengF, et al.Evolutionary topological design for phononic band gap crystals. Struct Multidiscip Optim2016; 54(3): 595–617.
31.
JiaZChenYYangH, et al.Designing phononic crystals with wide and robust band gaps. Phys Rev Appl2018; 9(4): 044021.
32.
BrunMMovchanABJonesIS. Phononic band gap systems in structural mechanics: finite slender elastic structures and infinite periodic waveguides. J Vib Acoust2013; 135(4): 041013.
33.
GueddidaAZhangVCarpentierL, et al.Phononic crystal made of silicon ridges on a membrane for liquid sensing. Sensors2023; 23(4): 2080.
34.
BabakiJNazariF. Heterostructure based demultiplexer using solid–solid phononic crystal ring resonators. J. Phys. D2020; 53(37): 375301.
