This study demonstrates a vertically integrated environment sensor with a fluorescence quenching based gas sensor [1] and a resistive temperature detector (RTD) using the TSMC standard CMOS process (Fig. 1a). Features of this study are (Fig. 1): (1) integration of photo-sensors, thermal-isolation structure, temperature, and optical based gas-sensing films using CMOS and polymer dispensing technologies, (2) multiple optical sensors equipped with thermal compensation unit (thermometer) are monolithically integrated, (3) heterogeneous integration with LED can reduce the size of gas sensor, (4) various sensing films can be prepared for multiple gases detection. Measurements show the results of sensitivity at room temperature and under influence of temperature variation. A sensitivity of 19.7 (μA/%) for O 2 (sensing range: 16-50% oxygen concentration) is achieved at room temperature and the sensitivity of the gas sensor decreases from 9.2μA/% to 1.7μA/% as the environment temperature increases from ~40°C to ~80°C. The monolithically integrated thermometer enables the on-site temperature monitoring for sensing signal compensation.

Monolithic Integrated CMOS-MEMS Fluorescence Quenching Gas Sensor and Resistive Temperature Detector (RTD) for Temperature Compensation

In recent times, the oxygen-quenching fluorescent-dye-
incorporated paint is emerging as a good sensor for surface-flow visualization studies. The first step in developing this paint is to develop a reliable optical sensor for oxygen, based on fluorescence quenching. In this document, the theoretical principles involved and the experimental approaches for development of optical oxygen sensor are briefly outlined. Besides, the candidate materials suitable for investigation and the methods of immobilising them on a solid matrix for studying their properties are also discussed.

Oxygen sensors based on fluorescence quenching

Corneal endothelial cells (CECs) are very important for the maintenance of corneal transparency. However, in vitro, CECs display limited proliferation and loss of phenotype via endothelial to mesenchymal transformation (EMT) and cellular senescence. In this study, we demonstrate that continuous supplementary nutrition using a perfusion culture bioreactor and three-dimensional (3D) spheroid culture can be used to improve CEC expansion in culture and to construct a tissue-engineered CEC layer. Compared with static culture, perfusion-derived CECs exhibited an increased proliferative ability as well as formed close cell-cell contact junctions and numerous surface microvilli. We also demonstrated that the CEC spheroid culture significantly down-regulated gene expression of the proliferation marker Ki67 and EMT-related markers Vimentin and α-SMA, whereas the gene expression level of the CEC marker ATP1A1 was significantly up-regulated. Furthermore, use of the perfusion system in conjunction with a spheroid culture on decellularized corneal scaffolds and collagen sheets promoted the generation of CEC monolayers as well as neo-synthesized ECM formation. This study also confirmed that a CEC spheroid culture on a curved collagen sheet with controlled physiological intraocular pressure could generate a CEC monolayer. Thus, our results show that the use of a perfusion system and 3D spheroid culture can promote CEC expansion and the construction of tissue-engineered corneal endothelial layers in vitro.

/pdf/in-vitro-biomimetic-platforms-featuring-a-perfusion-system-15kisyaom5.pdf

In vitro biomimetic platforms featuring a perfusion system and 3D spheroid culture promote the construction of tissue-engineered corneal endothelial layers

In this paper, a theoretical model of a multimode optical fiber based fluorescence sensor was proposed and established with the aims to optimize specific physical parameters of the sensor including the refractive index of the fluorescent matrix, external diameter and the length of sensing fiber probe which were calculated using the beam propagation method. The plane wave at wavelengths of 395 or 505 nm was used as the excitation light source. The excitation light power in the coating layer was calculated to obtain more excitation fluorescence. The change of fluorescence intensity with structural differences of the parameters was analyzed. The theoretical results showed that for a pure silica fiber using a matrix of higher refractive index (>1.458) material was effective in improving fluorescence performance. The optimized external diameter of the sensing fiber probe was found to be >206 μm with a 200 µm fiber core diameter when the refractive index of the sensing layer is 1.49. Increasing the thickness of the sensing layer increased the level of fluorescence excitation. The fluorescence intensity excited by 395 nm light is stronger than that of light at 505 nm.

Optimal design of a fluorescence oxygen sensing probe based on multimode optical fibers

An oxygen sensor is designed using a fluorescent substance PtOEP (platinum-octaethyl-porphyrin) as an indicator, based on the principle of fluorescence quenching Design idea is that: first, square wave modulation for LED excitation light source is made; second, the light irradiates in PMMA (Polymethyl Methacrylate) with fluorescent indicator, which produces fluorescence excitation and then fluorescence intensity also shows square wave change; Last the relationship between the oxygen concentration and fluorescence intensity is calibrated using gas mixer The sensor has high precision, good stability and repeatability, and has faster response speed The sensor can be used to measure the unknown environment (such as animal cell culture environment) of oxygen con- centration

Experiment Research of PtOEP Oxygen Sensor

A fluorescence fiber sensor based on step-index multimode optical fibers is simulated and design by beam propagation method with Beamprop module of Rsoft-CAD software, in the requirement of the much more exciting light in fluorescent material coated on the fiber core. The normalized exciting light power in the coating layer is calculated and analyzed. According to the numerical optimal results, the refractive index n o of fluorescent material layer is 1.49, and the optimal external diameter of coated layer should be greater than 206µm.

/pdf/optimal-design-of-the-fluorescence-sensors-based-on-step-4zyelz0g8l.pdf

Optimal design of the fluorescence sensors based on step-index multimode optical fibers

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Rongsheng Chen

Author Tools

Chat about Author

Papers

Optimal design of a fluorescence oxygen sensing probe based on multimode optical fibers

Experiment Research of PtOEP Oxygen Sensor

Optimal design of the fluorescence sensors based on step-index multimode optical fibers