Self-powered non-reciprocal phononic logic gates

Abstract Mechanical computing provides an information processing method adapting and interacting with the environment via living materials. As in electronic computing, power supply in mechanical computing is still the challenge. Designing self-powered logic gates can expand application scenarios of mechanical computing for environmental interaction. Here we formulate a framework of self-powered phononic logic gates as the basis for mechanical computing of the integrated acoustic circuit. Via tuning non-reciprocal bands, resonant band and obstacle band of a topologically imbalanced graded phononic crystal that breaks the spatial inversion symmetry, complete seven Boolean logic gates are realized on one metamaterial. The input of the logic gate, Lamb wave, is converted to the electric signal as the self-powered output by combination of the superior evanescent effect of the defect mode and the positive piezoelectric effect. An exemplify real-time heart rate monitoring powered by the graded phononic crystal is demonstrated for high-density energy conversion. The self-powered non-reciprocal phononic logic gates can be implemented on any length scale and broad external conditions.