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Author

Guoqing Fu

Other affiliations: University of Florida
Bio: Guoqing Fu is an academic researcher from Tufts University. The author has contributed to research in topics: Metamaterial antenna & Responsivity. The author has an hindex of 5, co-authored 14 publications receiving 205 citations. Previous affiliations of Guoqing Fu include University of Florida.

Papers
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Journal ArticleDOI
TL;DR: Here, pH‐responsive hydrogel fibers are presented that can be used for long‐term monitoring of epidermal wound condition and can act as a point‐of‐care device for monitoring the wound healing process.
Abstract: Epidermal pH is an indication of the skin's physiological condition. For example, pH of wound can be correlated to angiogenesis, protease activity, bacterial infection, etc. Chronic nonhealing wounds are known to have an elevated alkaline environment, while healing process occurs more readily in an acidic environment. Thus, dermal patches capable of continuous pH measurement can be used as point-of-care systems for monitoring skin disorder and the wound healing process. Here, pH-responsive hydrogel fibers are presented that can be used for long-term monitoring of epidermal wound condition. pH-responsive dyes are loaded into mesoporous microparticles and incorporated into hydrogel fibers using a microfluidic spinning system. The fabricated pH-responsive microfibers are flexible and can create conformal contact with skin. The response of pH-sensitive fibers with different compositions and thicknesses are characterized. The suggested technique is scalable and can be used to fabricate hydrogel-based wound dressings with clinically relevant dimensions. Images of the pH-sensing fibers during real-time pH measurement can be captured with a smart phone camera for convenient readout on-site. Through image processing, a quantitative pH map of the hydrogel fibers and the underlying tissue can be extracted. The developed skin dressing can act as a point-of-care device for monitoring the wound healing process.

151 citations

Journal ArticleDOI
TL;DR: This work proposes a low cost solution by repurposing the food’s barcode as a colorimetric sensor array to monitor food condition, which has the potential to reduce food waste and eliminate food-borne illness.

90 citations

Proceedings ArticleDOI
18 Jun 2017
TL;DR: In this article, a disposable paper-based optical sensor arranged as barcode for monitoring food spoilage is presented, which is embedded in the food packaging and monitored using smart phone.
Abstract: In this work, we present a disposable paper-based optical sensor arranged as barcode for monitoring food spoilage. The color-changing barcode is embedded in the food packaging and monitored using smart phone. The color change of different optical sensing dyes that make up the barcode is due to the emission of volatile organic compounds (VOCs) from food. Different geometric shapes are assigned to each sensing dye for identification. The sensor fabrication is low-tech and easy to perform. A smart phone quantifies the color change in the barcode food sensor, which provides a non-contact metric of food freshness/spoilage.

17 citations

Journal ArticleDOI
TL;DR: In this article, a low profile electrically small antenna for near-field wireless power and data telemetry employing a metamaterial Split Ring Resonator (SRR) antenna is proposed.
Abstract: Radio Frequency Identification (RFID) and implantable biomedical devices need efficient power and data transfer with very low profile antennas We propose a low profile electrically small antenna for near-field wireless power and data telemetry employing a metamaterial Split Ring Resonator (SRR) antenna SRRs can be designed for operation over wide frequencies from RF to visible However, they are inherently narrowband making them sensitive to component mismatch with respect to external transmit antenna Here we propose an embedding of a non-foster impedance circuitry into the metamaterial SRR structure that imparts conjugate negative complex impedance to this resonator antenna thereby increasing the effective bandwidth and thus overcoming the fundamental limit for efficient signal coupling We demonstrate the concept through extensive numerical simulations and a prototype system at the board level using discrete off-the-shelf components and printed circuit SRR antenna at 500 MHz We show that the power transfer between SRR receive antenna and the external transmit loop antenna is broadened by almost 400 MHz which corresponds to increase in {\Delta}f/fC from 049 to 165, before and after non-foster circuit activation

9 citations

Journal ArticleDOI
TL;DR: An embedding of a non-foster impedance circuitry into the metamaterial SRR structure that imparts conjugate negative complex impedance to this resonator antenna thereby increasing the effective bandwidth and thus overcoming the fundamental limit for efficient signal coupling.
Abstract: Wireless powering of implantable biomedical devices and smart radio frequency identification (RFID) tags with very low profile antennas is desired. We propose a low profile electrically small antenna for near-field wireless power telemetry employing a metamaterial Split Ring Resonator (SRR) antenna. SRRs can be designed for operation over wide frequencies from RF to visible. However, they are inherently narrowband making them sensitive to component mismatch with respect to external transmit antenna. Here, we propose an embedding of a non-foster impedance circuitry into the metamaterial SRR structure that imparts conjugate negative complex impedance to this resonator antenna thereby increasing the effective bandwidth and thus overcoming the fundamental limit for efficient signal coupling. We demonstrate the concept through extensive numerical simulations and a prototype system at the board level using discrete off-the-shelf components and printed circuit SRR antenna at 500 MHz. We show that the power trans...

8 citations


Cited by
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Journal ArticleDOI
TL;DR: A comprehensive review on the development and state of the art of colorimetric and fluorometric sensor arrays is presented and the various chemometric and statistical analyses of high-dimensional data are presented and critiqued in reference to their use in chemical sensing.
Abstract: A comprehensive review on the development and state of the art of colorimetric and fluorometric sensor arrays is presented Chemical sensing aims to detect subtle changes in the chemical environment by transforming relevant chemical or physical properties of molecular or ionic species (ie, analytes) into an analytically useful output Optical arrays based on chemoresponsive colorants (dyes and nanoporous pigments) probe the chemical reactivity of analytes, rather than their physical properties (eg, mass) The chemical specificity of the olfactory system does not come from specific receptors for specific analytes (eg, the traditional lock-and-key model of substrate-enzyme interactions), but rather olfaction makes use of pattern recognition of the combined response of several hundred olfactory receptors In a similar fashion, arrays of chemoresponsive colorants provide high-dimensional data from the color or fluorescence changes of the dyes in these arrays as they are exposed to analytes This provides chemical sensing with high sensitivity (often down to parts per billion levels), impressive discrimination among very similar analytes, and exquisite fingerprinting of extremely similar mixtures over a wide range of analyte types, in both the gas and liquid phases Design of both sensor arrays and instrumentation for their analysis are discussed In addition, the various chemometric and statistical analyses of high-dimensional data (including hierarchical cluster analysis (HCA), principal component analysis (PCA), linear discriminant analysis (LDA), support vector machines (SVMs), and artificial neural networks (ANNs)) are presented and critiqued in reference to their use in chemical sensing A variety of applications are also discussed, including personal dosimetry of toxic industrial chemical, detection of explosives or accelerants, quality control of foods and beverages, biosensing intracellularly, identification of bacteria and fungi, and detection of cancer and disease biomarkers

639 citations

Journal ArticleDOI
TL;DR: The pathophysiology of chronic wounds is discussed and then the materials used for engineering drug delivery systems are discussed, and the architecture of the delivery platform and its ability to modulate drug delivery are discussed.

440 citations

Journal ArticleDOI
TL;DR: Consumer trends in wearable electronics, commercial and emerging devices, and fabrication methods are discussed, and real‐time monitoring of vital signs using biosensors, stimuli‐responsive materials for drug delivery, and closed‐loop theranostic systems are reviewed.
Abstract: Wearables as medical technologies are becoming an integral part of personal analytics, measuring physical status, recording physiological parameters, or informing schedule for medication. These continuously evolving technology platforms do not only promise to help people pursue a healthier life style, but also provide continuous medical data for actively tracking metabolic status, diagnosis, and treatment. Advances in the miniaturization of flexible electronics, electrochemical biosensors, microfluidics, and artificial intelligence algorithms have led to wearable devices that can generate real-time medical data within the Internet of things. These flexible devices can be configured to make conformal contact with epidermal, ocular, intracochlear, and dental interfaces to collect biochemical or electrophysiological signals. This article discusses consumer trends in wearable electronics, commercial and emerging devices, and fabrication methods. It also reviews real-time monitoring of vital signs using biosensors, stimuli-responsive materials for drug delivery, and closed-loop theranostic systems. It covers future challenges in augmented, virtual, and mixed reality, communication modes, energy management, displays, conformity, and data safety. The development of patient-oriented wearable technologies and their incorporation in randomized clinical trials will facilitate the design of safe and effective approaches.

327 citations

Journal ArticleDOI
01 Aug 2018-Small
TL;DR: A smart and automated flexible wound dressing with temperature and pH sensors integrated onto flexible bandages that monitor wound status in real-time to address unmet medical need and has the potential to significantly impact the treatment of chronic wounds.
Abstract: Chronic wounds are a major health concern and they affect the lives of more than 25 million people in the United States. They are susceptible to infection and are the leading cause of nontraumatic limb amputations worldwide. The wound environment is dynamic, but their healing rate can be enhanced by administration of therapies at the right time. This approach requires real-time monitoring of the wound environment with on-demand drug delivery in a closed-loop manner. In this paper, a smart and automated flexible wound dressing with temperature and pH sensors integrated onto flexible bandages that monitor wound status in real-time to address this unmet medical need is presented. Moreover, a stimuli-responsive drug releasing system comprising of a hydrogel loaded with thermo-responsive drug carriers and an electronically controlled flexible heater is also integrated into the wound dressing to release the drugs on-demand. The dressing is equipped with a microcontroller to process the data measured by the sensors and to program the drug release protocol for individualized treatment. This flexible smart wound dressing has the potential to significantly impact the treatment of chronic wounds.

254 citations

Journal ArticleDOI
TL;DR: This review discusses recent developments in the field of highly integrated mobile and wearable point-of-care testing (POCT) systems and highlights aspects of sample handling platforms, recognition elements and sensing methods, and new materials for signal transducers and powering devices for integration into mobile or wearable POCT systems.
Abstract: The rapid growth of research in the areas of chemical and biochemical sensors, lab-on-a-chip, mobile technology, and wearable electronics offers an unprecedented opportunity in the development of mobile and wearable point-of-care testing (POCT) systems for self-testing. Successful implementation of such POCT technologies leads to minimal user intervention during operation to reduce user errors; user-friendly, easy-to-use and simple detection platforms; high diagnostic sensitivity and specificity; immediate clinical assessment; and low manufacturing and consumables costs. In this review, we discuss recent developments in the field of highly integrated mobile and wearable POCT systems. In particular, aspects of sample handling platforms, recognition elements and sensing methods, and new materials for signal transducers and powering devices for integration into mobile or wearable POCT systems will be highlighted. We also summarize current challenges and future prospects for providing personal healthcare with sample-in result-out mobile and wearable POCT.

253 citations