THz waves have garnered significant attention across multiple domains, particularly in high-sensitivity sensing applications. Metamaterials are applicable in THz sensors owing to their exceptional sensitivity, particularly in refractive index measurement and pesticide identification. This paper proposes a THz metamaterial sensor for detecting ether kresoxim-methyl. The sensor comprises a periodic array of silicon cylindrical trimers organized on a silicon substrate. Resonances in the guided mode, dictated by bound states in the continuum spectrum, can be stimulated by meticulously configuring the geometric arrangement of the silicon column trimer. The sensor demonstrates a Q-value of up to 143 at the resonant frequency. The detection of pesticide residues achieved high sensitivity and specificity, with a detection limit of 37.74 μg/cm². This study presents a novel alternative for THz metamaterial sensors characterized by high sensitivity and a broad spectrum of pesticide concentration detection. The sensor platform developed in this paper, utilizing conventional CMOS technology, is posited as a potential detection instrument for herbicide and pesticide residues in agriculture and food.

Terahertz (THz) spectroscopy, an advanced label-free sensing method, offers significant potential for biomolecular detection and quantitative analysis in biological samples. Although broadband fingerprint enhancement compensates for limitations in detection capability and sensitivity, the complex optical path design in operation restricts its broader adoption. This paper proposes a multi-degree-of-freedom stretchable metasurface that supports magnetic dipole resonance to enhance the broadband THz fingerprint detection of trace analytes. The metasurface substrate and unit cell structures are constructed using polydimethylsiloxane. By adjusting the sensor’s geometric dimensions or varying the incident angle within a narrow range, the practical optical path is significantly simplified. Simultaneously, the resonance frequency of the transmission curve is tuned, achieving high sensitivity for effectively detecting cinnamoylglycine. The results demonstrate that the metasurface achieves a high-quality factor of 770.6 and an excellent figure of merit of 777.2, significantly enhancing the THz sensing capability. Consequently, the detection sensitivity for cinnamoylglycine can reach 24.6 µg·cm⁻². This study offers critical foundations for applying THz technology to biomedical fields, particularly detecting urinary biomarkers for diseases like gestational diabetes.

This study establishes a model for the motion path and collision detection of the bench dragon by analyzing spiral and motion trajectories, describing the system's motion characteristics through mathematical models and differential equations, and verifying the model's reliability. Given the current lack of systematic research in this area, this paper pioneers a relevant model for detailed analysis. Initially, a differential equation model for θ and t was developed based on the spiral equation and polar coordinate arc length formula, with the improved Runge-Kutta algorithm used for iterative solving to determine connection point positions and finite difference methods applied for velocity calculations. The Separating Axis Theorem was then introduced for collision detection, and a function relating pitch to turning space was initialized, with traversal of possible pitches and step lengths revealing a minimum collision pitch of 0.452m. Finally, geometric methods derived the positions and velocities of connection points on the shortest path, demonstrating that the turning path length is fixed and unoptimizable. The model successfully generated motion paths, collision times, and minimum pitch under varying conditions, with results visualized in images and tables, effectively capturing the bench dragon's motion characteristics while ensuring reliability through numerical validation and error analysis. Future work may focus on algorithmic optimization to enhance computational efficiency.