Bistable metamaterial for switching and cascading elastic vibrations

Abstract

The realization of acoustic devices analogous to electronic systems, like diodes, transistors, and logic elements, suggests the potential use of elastic vibrations (i.e., phonons) in information processing, for example, in advanced computational systems, smart actuators, and programmable materials. Previous experimental realizations of acoustic diodes and mechanical switches have used nonlinearities to break transmission symmetry. However, existing solutions require operation at different frequencies or involve signal conversion in the electronic or optical domains. Here, we show an experimental realization of a phononic transistor-like device using geometric nonlinearities to switch and amplify elastic vibrations, via magnetic coupling, operating at a single frequency. By cascading this device in a tunable mechanical circuit board, we realize the complete set of mechanical logic elements and interconnect selected ones to execute simple calculations.phononic metamaterials | tunable materials | phonon switching and cascading | phononic computing | acoustic transistor T he idea of realizing a mechanical computer has a long established history (1). The first known calculators and computers were both mechanical, as in Charles Babbage's concept of a programmable computer and Ada Lovelace's first description of programing (2). However, the discovery of electronic transistors rapidly replaced the idea of mechanical computing. Phononic metamaterials, used to control the propagation of lattice vibrations, are systems composed of basic building blocks, (i.e., unit cells) that repeat spatially. These materials exhibit distinct frequency characteristics, such as band gaps, where elastic/acoustic waves are prohibited from propagation. Potential applications of phononic metamaterials in computing can range from thermal computing (3-5) (at small scales) to ultrasound and acousticbased computing (6, 7) (at larger scales). Phononic devices analogous to electronic or optical systems have already been demonstrated. For example, acoustic switches (8, 9), rectifiers (10, 11), diodes (12-15), and lasers (16, 17) have been demonstrated both numerically and experimentally. Recently, phononic computing has been suggested as a possible strategy to augment electronic and optical computers (18) or even facilitate phononicbased quantum computing (19,20). All-phononic circuits have been theoretically proposed (21, 22) and phononic metamaterials (23-26) have been identified as tools to perform basic logic operations (6, 7). Electromechanical logic (27) and transistors (28) operating using multiple frequencies have also been demonstrated. Most of these devices operate using electronic signals (26) and/or operate at mixed frequencies. When different frequencies are needed for information to propagate, it becomes difficult, if not impossible, to connect multiple devices in a circuit.Electronic transistors used in today's electronic devices are characterized by their ability to switch and amplify electronic signals. Conventional field-effect tran...

All-acoustic signal modulation and logic operation via defect induced cavity effects in phononic crystal coupled-resonator acoustic waveguides

“…Phononic and mechanical waves may not provide information transmission speeds comparable with electronics due to higher possible transmission rates of electrons and electronic information. The proposal to use phononic structures for logic elements or acoustic signal treatment for logic operation has been reported [21][22][23][24]. However, the reported results here can enable one the possible design of novel acoustic devices not only for the selective transmission but also the spatial control of acoustic energy flow, which is not used in the cited references.…”

“…Currently, ultrasonic logic elements, including acoustic switches, are based on modulation of acoustic throughput signals using nonlinear responses in the materials comprising a PnC [21,22]. Cylindrical polyvinylchloride inclusions squarely dispersed in air were used to build Boolean logic gates, specifically, for NAND, XOR, and NOT functions.…”

Enhanced stability, bistability, and exceptional points in saturable active photonic couplers

“…we remark that bistability domains never share a common boundary with domains where no stable NS exist; they only touch each other via isolated points. The bistability reported in Figs 2(c) and 2(d), accompanied by hysteresis, is indispensable for information processing in various setups including acoustic [50] or thermal [51] components, and for photonic memory primarily in optical structures [41]. In Figs 3 we display stability maps, as in Figs 2, where we scan the whole range of saturation coefficient ε.…”

Design and Testing of Bistable Lattices with Tensegrity Architecture and Nanoscale Features Fabricated by Multiphoton Lithography

“…Metamaterials comprised of lattice members are spatial periodic structures with unprecedented physical properties, mainly derived from the architecture of the repeated substructure, rather than the nature of the constituent materials. It is worth noting that extraordinary strength-to-weight and stiffness-to-weight ratios, frequency bandgaps, negative overall elastic moduli, negative mass density, auxeticity and solitary wave propagation represent characteristic and unconventional properties of such systems [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], as well as a multistable mechanical response [19][20][21][22][23][24][25][26][27][28]. However, the additive manufacturing of multi-cell realizations of mechanical metamaterials remains a challenge at present, due to the difficulty of reproducing the desired behaviors at small scales [8,9,[29][30][31][32].…”