Hao Zhang's research while affiliated with Tianjin University and other places

Publications (6)

Article
Full-text available
Low-abundance biomolecule detection is very crucial in many biological and medical applications. In this paper, we present a novel electrolyte-gated graphene field-effect transistor (EGFET) biosensor consisting of acoustic tweezers to increase the sensitivity. The acoustic tweezers are based on a high-frequency bulk acoustic resonator with thousand...
Article
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 simu...
Article
Full-text available
Two-dimensional (2D) transition metal dichalcogenides (TMDCs) semiconducting materials have recently attracted wide attention and been regarded as promising building blocks for chemical sensors due to their high surface-to-volume ratio. However, their low response hinders the realization of high-performance 2D TMDCs chemical sensors. Here, we demon...
Article
We developed a highly sensitive humidity sensor based on the combination of ultrahigh-frequency film bulk acoustic resonator (FBAR) and nano-assembled polyelectrolyte (PET) thin films. The water molecule absorption efficiency was optimized by forming loosely-packed PET nanostructures. Then, the humidity sensing characteristics were analyzed in term...
Article
A high-resolution humidity sensor based on MEMS FBAR with spin-coated PVA thin film is reported. The sensors exhibit very high sensitivity to water vapor and are able to detect down to 0.08 % change in relative humidity by monitoring the shift in series resonant frequency of the FBARs. The integration of these devices with CMOS oscillating circuits...

Citations

... The extremely low abundance of biomolecules in most sensing applications is the most well-known challenge. With the aim of reaching ever lower bio-detection limits, Yan Chen et al. [2] report on the development of an acoustic concentrator, named "acoustic tweezers", which uses high frequency longitudinal acoustic waves to promote the concentration of the target molecules in the detection area of an electrolyte-gated graphene field effect transistor. The effect of the acoustic tweezers was validated under the microscope by IgG labelled with green fluorescence, and by comparison of the FET response (Dirac point shift) with and without acoustic accumulation. ...
... As a consequence, TMDs have been considered a model material for chemical sensors as interactions on their surfaces are mostly limited to physisorption, and their excellent surface-to-volume ratio makes the accumulative impact on their carrier concentration relatively large. This has led TMDs such as molybdenum disulfide (MoS 2 ) and molybdenum ditelluride (MoTe 2 ) to be particularly sensitive to molecules of nitrogen dioxide (NO 2 ) 24,28-30 and ammonia (NH 3 ) [30][31][32][33] . Interestingly, the sensitivity has been reported selectively enhanced depending on the number of layers 34 . ...
... There are various ways of acquiring air with specified humidity. The most reliable method is obtained by mixing dry gas (relative humidity (RH) 0% RH) with watersaturated gas in strictly defined proportions [1][2][3][4][5][6][7]. However, this method requires precise control of both gas flows and results in high equipment costs. ...
... The direction of lateral flow is pointed by the blue arrow. acoustic device in the crosssectional plane, which we refer to as the "stereo acoustic stream" (SteAS) (43,44). The chip is consisted of the UHF BAW device and microfluidics. ...
... The shape of the device determines the profile of the AST. In this work, we take the best performance (quality factor, resonant frequency) as the priority principle of the device design; thus, a pentagonal UHF device with an area of 20 k μm 2 was used in this system 65,66 . Here, a 3D simulation model was applied to deeply analyze the interactions between lateral flow and the AST in 3D space. ...