RESUMEN
In order to overcome the simplicity and instability of micron cantilever membrane structure, sacrificial layer technology and multi-layer heterogeneous material composite stacking technology were designated. Based on the research with respect to a multi-layer heterogeneous cantilever beam structure, multi-layer heterogeneous material composite, and sacrificial layer release craft, different characteristics of sacrificial layer material and film preparation craft were analyzed. According to these results, the suitable film preparation craft was generated to reduce the stress between materials and to improve the reliability and percentage of finished products. Our work put multi-layer material composite micro-cantilever beam structure into practice, and accelerated the manufacturing of a micro-acceleration sensor and vibration sensor in the future.
RESUMEN
In this paper, we proposed an all-sapphire-based extrinsic Fabry-Perot interferometer (EFPI) pressure sensor based on an optimized wet etching process, aiming to improve the quality of the interference signal. The sapphire pressure sensitive diaphragm (SPSD) was fabricated by wet etching solutions with different mixture ratios of H3PO4 and H2SO4 at 280°C. The differences of mixture ratios affect the surface roughness of SPSD. SPSDs with surface roughness of 3.91nm and 0.39nm are obtained when the mixture ratios of H3PO4 and H2SO4 is 1:1 and 1:3, respectively. We constructed pressure sensing test system adopting these two kinds of SPSD and performed comparative test. The experiment results show that the demodulation jump can be solved and cavity length fluctuation is decreased to ±5nm when the surface roughness of SPSD is 0.39nm.
RESUMEN
This paper presents the design and synthesis of star-shaped copolymers with two poly[2-(diethylamino)ethyl methacrylate] and poly(ethylene glycol) blocks linked via a disulfide bond and each end of the four arms capped by folic acid (FA), from which the prepared nanodrug carriers simultaneously possess pH/redox dual response and active targeting functions. The polymer micelles exhibit excellent stability as reflected by their low critical micelle concentration values of 1.03-2.51 mg/L. The doxorubicin (DOX)-loaded polymer micelles are in the range of 108 to 143 nm, and the DOX-loading capacities are found to be up to 32.3%. The sensitive pH and redox responses are demonstrated by examining the drug release behaviors under the varied acidic condition from pH 7.4 to 5.0 and the glutathione concentrations from 0 to 10 mM, respectively. Moreover, the observation of confocal laser scanning microscopy confirms that the functionalization of arm ends by FA indeed enhances the internalization of DOX-loaded micelle particles in HeLa cells. As a result, the DOX-loaded nanocarriers can deliver therapeutic drugs to target HeLa cells, and the viability of HeLa cells (10.1%) approaches the value of the pristine DOX (9.98%), showing promising application as drug delivery nanocarriers for safe and highly efficient cancer therapy.