High-Q two-groove resonator for all-dielectric Bloch surface wave platform

We propose a simple integrated resonant structure for the Bloch surface wave platform, which consists of two subwavelength grooves patterned on the surface of a one-dimensional dielectric photonic crystal. We demonstrate that the investigated structure can operate in a parasitic-scattering-free regime and, in this case, provide unity transmittance and zero reflectance at resonance conditions associated with the excitation of a leaky mode of the structure localized at the central ridge formed by the grooves. The proposed structure may find application in integrated photonic devices for optical filtering and analog optical computing.

Band gap analysis of a three-mass locally resonant structure

A mass in a mass locally resonant system has been studied using a numerical and analytical method. This study is performed to compute the band gap and transmission coefficient of a mass–spring locally resonant system. A locally resonant structure is a periodic structure which exhibits negative effective properties in a certain frequency band and reveals band gaps below Bragg’s frequency. In this work, two substructures are attached with main mass so that the system will act as two masses in a mass system. It is found that the presented structure shows two band gaps below 500 Hz with negative effective properties. Addition of a third substructure with the main mass provides an additional band gap at low frequency. The position and width of band gaps can be tuned by changing the values of masses and stiffness.

A Novel Frequency Stabilization Approach for Mass Detection in Nonlinear Mechanically Coupled Resonant Sensors

Frequency stabilization can overcome the dependence of resonance frequency on amplitude in nonlinear microelectromechanical systems, which is potentially useful in nonlinear mass sensor. In this paper, the physical conditions for frequency stabilization are presented theoretically, and the influence of system parameters on frequency stabilization is analyzed. Firstly, a nonlinear mechanically coupled resonant structure is designed with a nonlinear force composed of a pair of bias voltages and an alternating current (AC) harmonic load. We study coupled-mode vibration and derive the expression of resonance frequency in the nonlinear regime by utilizing perturbation and bifurcation analysis. It is found that improving the quality factor of the system is crucial to realize the frequency stabilization. Typically, stochastic dynamic equation is introduced to prove that the coupled resonant structure can overcome the influence of voltage fluctuation on resonance frequency and improve the robustness of the sensor. In addition, a novel parameter identification method is proposed by using frequency stabilization and bifurcation jumping, which effectively avoids resonance frequency shifts caused by driving voltage. Finally, numerical studies are introduced to verify the mass detection method. The results in this paper can be used to guide the design of a nonlinear sensor.

Study on a collecting structure for impact energy and its dynamic characteristics

The impact energy harvesting technology is studied in this paper, a piezoelectric harvesting structure with additional resonant structure including spring mass components is proposed, and the system dynamics model of the structure is studied. The influence of the structural parameters of spring mass block on the system output voltage is studied by using the model. The research results have certain application value for impact energy harvesting.

Liquid metal-based metamaterial with high-temperature sensitivity: Design and computational study

This article proposes a metamaterial-based temperature sensor with high sensitivity using the thermally tunable liquid metal of mercury. The response of the metamaterial at different temperatures is theoretically investigated. In the merit of the temperature-sensitive thermal expanding of the embedded mercury resonant structure, different absorption peak frequencies can be observed at different temperatures, which enables the proposed metamaterial capability of temperature sensing. The numerical simulations show that the temperature sensitivity of the proposed sensor can reach up to 27.64 MHz/°C within the range of 0–21.8°C. The calculated electric field and surface current distributions illustrate that the high sensitivity is originated from the dual-dipole mode of the resonant structure. Meanwhile, the dependence of the structural dimensions on temperature sensitivity is discussed to optimize the sensor design. The proposed strategy paves a new way for developing temperature sensors with high sensitivity.