Measurement of hemostatic parameters is essential for patients receiving long-term oral anticoagulant agents. In this paper, we present a shear mode bulk acoustic resonator based on an inclinedc-axis aluminum nitride (AlN) film for monitoring the human hemostatic parameters. During the blood coagulation process, the resonant frequency of the device decreases along with a step-ladder profile due to the viscosity change during the formation of fibers in blood, revealing the sequential coagulation stages. Two hemostatic parameters with clinical significance, prothrombin time (PT) along with its derived measure of international normalized ratio (INR), are determined from time-frequency curves of the device. Furthermore, the resonator is compared with a commercial coagulometer by monitoring the hemostatic parameters for one month in a patient taking the oral anticoagulant. The results are consistent. In addition, thanks to the excellent potential for integration, miniaturization and the availability of direct digital signals, the proposed device has promising application for point of care coagulation monitoring.Keywords:bulk acoustic wave;AlN film;hemostatic parameters;viscosity sensor
Detection of liquid viscosity is important from chemical engineering to daily safety. To match the emergence of internet of things, precise and fast viscosity determination is attracting intention in the society. However, most miniature viscometers face limitations such as high operation frequency, moving component, and non-linear sensing, etc. Herein, a flexible viscometer is developed via coupling the electromagnetic induction with inherent oscillation of a magnetized oscillator. The mechanism allows vibration of the oscillator to be electrically reflected using damping signals. By analyzing the damping factor from viscosity-dependent voltage profiles, viscosity of an unknown liquid can be accurately obtained. Furthermore, the 3D structures is developed with a dual-template method, which enables convenient and high-throughput preparations of devices with complex 3D structures. Via optimizing the structural and physical parameters, the “sphere” oscillator enables a linear relationship between the damping factor and the square root of viscosity for quantitative sensing in range of 0.01809–24.7 mPa s. The principle of electromagnetic induction renders the viscometer with superiorities of low operating frequency, remote sensing, self-powered and chemical stability. It is expected that the methodology and damping dominant mechanism will serve as a promising platform for cost-effective, portable and convenient viscosity detection for applications in diverse fluids.
On-chip integrating several functional components for developing integrated lab-on-a-chip microsystem remains as a challenge. In this work, by employing multiple microelectromechanical resonators both as actuators and sensors, on-chip heating, mixing and chemical reaction monitoring are successfully demonstrated. Mechanism studies using COMSOL simulations indicate that the local heating and mixing are induced by the acoustic wave attenuation during its transmission in liquid. On-line chemical reaction monitoring is realized by viscosity sensing using the same resonator through impedance analysis. Classic Diels-Alder reaction in a single droplet was performed to verify the feasibility of using such microsystem for mixing, heating and online reaction monitoring at microscale.
危险品化学品经营许可证（带存储）