Paper Session II-C - High-Resolution Integrated Micro Gyroscope for Space Applications

In this paper, an integrated capacitive gyroscope fabricated by CMOS-MEMS technology is presented. The CMOS-compatibility of the fabrication process enables full integration of the sensor with interface and signal conditioning circuitry on a single chip. The entire microstructure is single-crystal silicon based, resulting in large proof mass and good mechanical behaviors. Thus, high-resolution and high-robustness microgyroscopes can be obtained. With a resolution of about 0.01°/s/Hz112 , the fabricated gyroscope chip is only as small as 1.5mm by 2mm including the sensing elements and integrated electronics. The robustness, light weight and high performance make this type of MEMS gyroscope very suitable for space navigation applications where payload is critical. The on-chip capacitive sensing circuitry employs chopper stabilization technique to minimize the influence of 1/f noise. The on-chip circuits also include a two-stage fully differential amplifier and a DC feedback loop to cancel the DC offset. The CMOS fabrication was performed through MOSIS by using the 4-metal TSMC 0.35 μm CMOS process. The post-CMOS micromachining processing consists of only dry etch steps and uses the interconnect metal layers as etching masks. Single-crystal silicon (SCS) structures are produced by applying a backside etch and forming a 60μm-thick SCS membrane. This work is sponsored by NASA through the UCF/UF Space Research Initiative

A Low-Cost CMOS-MEMS Piezoresistive Accelerometer with Large Proof Mass

This paper reports a low-cost, high-sensitivity CMOS-MEMS piezoresistive accelerometer with large proof mass. In the device fabricated using ON Semiconductor 0.5 μm CMOS technology, an inherent CMOS polysilicon thin film is utilized as the piezoresistive sensing material. A full Wheatstone bridge was constructed through easy wiring allowed by the three metal layers in the 0.5 μm CMOS technology. The device fabrication process consisted of a standard CMOS process for sensor configuration, and a deep reactive ion etching (DRIE) based post-CMOS microfabrication for MEMS structure release. A bulk single-crystal silicon (SCS) substrate is included in the proof mass to increase sensor sensitivity. In device design and analysis, the self heating of the polysilicon piezoresistors and its effect to the sensor performance is also discussed. With a low operating power of 1.5 mW, the accelerometer demonstrates a sensitivity of 0.077 mV/g prior to any amplification. Dynamic tests have been conducted with a high-end commercial calibrating accelerometer as reference

Membrane Contact Demulsification: A Superhydrophobic ZIF-8@rGO Membrane for Water-in-Oil Emulsion Separation

Achieving a water–oil interface imbalance has been identified as a critical factor in the demulsification of water-in-oil emulsions. However, conventional demulsifying membranes generally break the interface balance by depending on a relatively high transmembrane pressure. Here, we present a “contact demulsification” concept to naturally and quickly achieve disruption of the water–oil interface balance. For this purpose, a novel demulsifying membrane with a high flux of the organic component has been developed via the simple vacuum assembly of zeolitic imidazolate framework-8 (ZIF-8)@reduced graphene oxide (rGO) microspheres (ZGS) on a polytetrafluoroethylene (PTFE) support, followed by immobilization processing in a polydimethylsiloxane (PDMS) crosslinking solution. Due to the micro-nano hierarchies of the ZGS, the prepared ZIF-8@rGO@PDMS/PTFE (ZGPP) membranes feature a unique superhydrophobic surface, which results in a water–oil interface imbalance when a surfactant-stabilized water-in-oil emulsion comes into contact with the membrane surface. Under a low transmembrane pressure of 0.15 bar (15 kPa), such membranes show an excellent separation efficiency (∼99.57%) and a high flux of 2254 L·m−2·h−1, even for surfactant-stabilized nanoscale water-in-toluene emulsions (with an average droplet size of 57 nm). This “contact demulsification” concept paves the way for developing next-generation demulsifying membranes for water-in-oil emulsion separation

Impact of drought on soil microbial biomass and extracellular enzyme activity

IntroductionWith the continuous changes in climate patterns due to global warming, drought has become an important limiting factor in the development of terrestrial ecosystems. However, a comprehensive understanding of the impact of drought on soil microbial activity at a global scale is lacking.MethodsIn this study, we aimed to examine the effects of drought on soil microbial biomass (carbon [MBC], nitrogen [MBN], and phosphorus [MBP]) and enzyme activity (β-1, 4-glucosidase [BG]; β-D-cellobiosidase [CBH]; β-1, 4-N-acetylglucosaminidase [NAG]; L-leucine aminopeptidase [LAP]; and acid phosphatase [AP]). Additionally, we conducted a meta-analysis to determine the degree to which these effects are regulated by vegetation type, drought intensity, drought duration, and mean annual temperature (MAT).Result and discussionOur results showed that drought significantly decreased the MBC, MBN, and MBP and the activity levels of BG and AP by 22.7%, 21.2%, 21.6%, 26.8%, and 16.1%, respectively. In terms of vegetation type, drought mainly affected the MBC and MBN in croplands and grasslands. Furthermore, the response ratio of BG, CBH, NAG, and LAP were negatively correlated with drought intensity, whereas MBN and MBP and the activity levels of BG and CBH were negatively correlated with drought duration. Additionally, the response ratio of BG and NAG were negatively correlated with MAT. In conclusion, drought significantly reduced soil microbial biomass and enzyme activity on a global scale. Our results highlight the strong impact of drought on soil microbial biomass and carbon- and phosphorus-acquiring enzyme activity

Extraction of valuable lanthanum, zirconium and lithium elements from solid electrolyte LI7LA3ZR2O12 (LLZO)

Valuable elements in lithium-ion batteries is a very significant secondary resource. Based on the recovery and recycling of the spent all-solid-state lithium-ion batteries in the future, we explore extracting valuable lanthanum, zirconium, and lithium elements from the solid electrolyte tetragonal phase LLZO by the leaching with the dilute sulfuric, and then by precipitation methods of double salts and carbonate salt, and recrystallization, respectively

Serum peptidome profiling for the diagnosis of colorectal cancer: Discovery and validation in two independent cohorts

Colorectal cancer (CRC) is one of the most common malignant neoplasms worldwide. Except for the existing fecal occult blood test, colonoscopy and sigmoidoscopy, no widely accepted in vitro diagnostic methods have been available. To identify potential peptide biomarkers for CRC, serum samples from a discovery cohort (100 CRC patients and 100 healthy controls) and an independent validation cohort (91 CRC patients and 91 healthy controls) were collected. Peptides were fractionated by weak cation exchange magnetic beads (MB-WCX) and analysed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDITOF MS). Five peptides (peaks at m/z 1895.3, 2020.9, 2080.7, 2656.8 and 3238.5) were identified as candidate biomarkers for CRC. A diagnostic panel based on the five peptides can discriminate CRC patients from healthy controls, with an accuracy of 91.8%, sensitivity of 95.6%, and specificity of 87.9% in the validation cohort. Peptide peaks at m/z 1895.3, 2020.9 and 3238.5 were identified as the partial sequences of complement component 4 (C4), complement component 3 (C3) and fibrinogen a chain (FGA), respectively. This study potentiated peptidomic analysis as a promising in vitro diagnostic tool for diagnosis of CRC. The identified peptides suggest the involvement of the C3, C4 and FGA in CRC pathogenesis

Detection of hepatitis A virus in shellfish and berries by digital polymerase chain reaction

Objective To establish a digital polymerase chain reaction (PCR) method for hepatitis A virus (HAV) in shellfish and berry foods. Methods After sample enrichment by proteinase K digestion polyethylene glycol method, RNA was extracted by high purity virus nucleic acid kit, and then digital PCR was used to detect HAV. Results This method had typical amplification, good repeatability and stability for HAV. The sensitivity of HAV in strawberry, raspberry and shellfish samples was 25.30 CCID50/20 g, 6.32 CCID50/20 g and 12.54 CCID50/2 g respectively, which means that the detection sensitivity of HAV was high. Conclusion This method is rapid, accurate, sensitive, and is suitable for the determination of HAV in shellfish and berry foods