Sensors in blockchain Altay, Alara; Learney, Robert; Güder, Firat ...
Trends in biotechnology (Regular ed.),
February 2022, 2022-02-00, 20220201, Volume:
40, Issue:
2
Journal Article
Peer reviewed
Blockchain, the technology behind bitcoin, has stimulated global conversation around digital decentralization to connect societies and economies. Connected low-cost sensors within Internet of Things ...(IoT) networks may soon perform measurements, exchange data, and make decisions automatically over decentralized networks; these systems could improve healthcare, the quality of goods, and supply chain efficiency.
Current methods of monitoring breathing require cumbersome, inconvenient, and often expensive devices; this requirement sets practical limitations on the frequency and duration of measurements. This ...article describes a paper‐based moisture sensor that uses the hygroscopic character of paper (i.e. the ability of paper to adsorb water reversibly from the surrounding environment) to measure patterns and rate of respiration by converting the changes in humidity caused by cycles of inhalation and exhalation to electrical signals. The changing level of humidity that occurs in a cycle causes a corresponding change in the ionic conductivity of the sensor, which can be measured electrically. By combining the paper sensor with conventional electronics, data concerning respiration can be transmitted to a nearby smartphone or tablet computer for post‐processing, and subsequently to a cloud server. This means of sensing provides a new, practical method of recording and analyzing patterns of breathing.
Internet‐enabled paper‐based sensor: A simple paper‐based sensor relying on changes in the humidity caused by breathing was fabricated (see picture). The electrical conductivity of the cellulose adsorbent varied as it was loaded with water from humid exhaled air.
Disposable sensors are low‐cost and easy‐to‐use sensing devices intended for short‐term or rapid single‐point measurements. The growing demand for fast, accessible, and reliable information in a ...vastly connected world makes disposable sensors increasingly important. The areas of application for such devices are numerous, ranging from pharmaceutical, agricultural, environmental, forensic, and food sciences to wearables and clinical diagnostics, especially in resource‐limited settings. The capabilities of disposable sensors can extend beyond measuring traditional physical quantities (for example, temperature or pressure); they can provide critical chemical and biological information (chemo‐ and biosensors) that can be digitized and made available to users and centralized/decentralized facilities for data storage, remotely. These features could pave the way for new classes of low‐cost systems for health, food, and environmental monitoring that can democratize sensing across the globe. Here, a brief insight into the materials and basics of sensors (methods of transduction, molecular recognition, and amplification) is provided followed by a comprehensive and critical overview of the disposable sensors currently used for medical diagnostics, food, and environmental analysis. Finally, views on how the field of disposable sensing devices will continue its evolution are discussed, including the future trends, challenges, and opportunities.
Disposable sensors are inexpensive and easy‐to‐use tools for short‐term monitoring or single‐shot measurements. An insight into the materials and fundamentals of sensors along with an extensive and critical overview of the recent disposable sensing devices in medical diagnostics, food, and environmental analysis is given. Lastly, future trends, challenges, and opportunities in the field of disposable sensors are discussed.
Exhaled breath contains a large amount of biochemical and physiological information concerning one’s health and provides an alternative route to noninvasive medical diagnosis of diseases. In the case ...of lung diseases, hydrogen peroxide (H2O2) is an important biomarker associated with asthma, chronic obstructive pulmonary disease, and lung cancer and can be detected in exhaled breath. The current method of breath analysis involves condensation of exhaled breath, is not continuous or real time, and requires two separate and bulky devices, complicating the periodic or long-term monitoring of a patient. We report the first disposable paper-based electrochemical wearable sensor that can monitor exhaled H2O2 in artificial breath calibration-free and continuously, in real time, and can be integrated into a commercial respiratory mask for on-site testing of exhaled breath. To improve precision for sensing H2O2, we perform differential electrochemical measurement by amperometry in which screen-printed Prussian Blue-mediated and nonmediated carbon electrodes are used for differential analysis. We were able to measure H2O2 in simulated breath in a concentration-dependent manner in real time, confirming its functionality. This proposed system is versatile, and by modifying the chemistry of the sensing electrodes, our method of differential sensing can be extended to continuous monitoring of other analytes in exhaled breath.
End-to-end design of wearable sensors Ates, H. Ceren; Nguyen, Peter Q.; Gonzalez-Macia, Laura ...
Nature reviews. Materials,
11/2022, Volume:
7, Issue:
11
Journal Article
Peer reviewed
Open access
Wearable devices provide an alternative pathway to clinical diagnostics by exploiting various physical, chemical and biological sensors to mine physiological (biophysical and/or biochemical) ...information in real time (preferably, continuously) and in a non-invasive or minimally invasive manner. These sensors can be worn in the form of glasses, jewellery, face masks, wristwatches, fitness bands, tattoo-like devices, bandages or other patches, and textiles. Wearables such as smartwatches have already proved their capability for the early detection and monitoring of the progression and treatment of various diseases, such as COVID-19 and Parkinson disease, through biophysical signals. Next-generation wearable sensors that enable the multimodal and/or multiplexed measurement of physical parameters and biochemical markers in real time and continuously could be a transformative technology for diagnostics, allowing for high-resolution and time-resolved historical recording of the health status of an individual. In this Review, we examine the building blocks of such wearable sensors, including the substrate materials, sensing mechanisms, power modules and decision-making units, by reflecting on the recent developments in the materials, engineering and data science of these components. Finally, we synthesize current trends in the field to provide predictions for the future trajectory of wearable sensors.Wearable sensors that access both biophysical and biochemical information can be used to monitor the physiological state of an individual and facilitate diagnosis. This Review examines the building blocks of wearable devices, including the substrate materials as well as the sensing, decision-making and power modules.
Electrically Activated Paper Actuators Hamedi, Mahiar M.; Campbell, Victoria E.; Rothemund, Philipp ...
Advanced functional materials,
April 19, 2016, Volume:
26, Issue:
15
Journal Article
Peer reviewed
Open access
This paper describes the design and fabrication of electrically controlled paper actuators that operate based on the dimensional changes that occur in paper when the moisture absorbed on the surface ...of the cellulose fibers changes. These actuators are called “Hygroexpansive Electrothermal Paper Actuators” (HEPAs). The actuators are made from paper, conducting polymer, and adhesive tape. They are lightweight, inexpensive, and can be fabricated using simple printing techniques. The central element of the HEPAs is a porous conducting path (used to provide electrothermal heating) that changes the moisture content of the paper and causes actuation. This conducting path is made by embedding a conducting polymer (PEDOT:PSS) within the paper, and thus making a paper/polymer composite that retains the porosity and hydrophilicity of paper. Different types of HEPAs (straight, precurved, and creased) achieved different types of motions (e.g., bending motion, accordion type motion). A theoretical model for their behavior is proposed. These actuators have been used for the manipulation of liquids and for the fabrication of an optical shutter.
Hygroexpansive electrothermal paper actuators (HEPAs) are fabricated from paper, conducting polymer and adhesive tape, and operate based on the moisture‐induced dimensional changes of paper. The central element of the HEPAs is a porous conducting path (used to provide electrothermal heating). A theoretical model for their behavior is proposed. These actuators can be used for the manipulation of liquids and for the fabrication of an optical shutter.
Near-field communication emerged as a high-security, wireless, short-range, data exchange technology nearly two decades ago; its ability to simultaneously transfer power and data between devices ...offers exciting opportunities for the design of miniature, battery-free and disposable sensing systems in health care and food quality monitoring.
We report an entirely new class of printed electrical gas sensors that are produced at near “zero cost”. This technology exploits the intrinsic hygroscopic properties of cellulose fibers within ...paper; although it feels and looks dry, paper contains substantial amount of moisture, adsorbed from the environment, enabling the use of wet chemical methods for sensing without manually adding water to the substrate. The sensors exhibit high sensitivity to water-soluble gases (e.g., lower limit of detection for NH3 < 200 parts-per-billion) with a fast and reversible response. The sensors show comparable or better performance (especially at high relative humidity) than most commercial ammonia sensors at a fraction of their price (<$0.02 per sensor). We demonstrate that the sensors proposed can be integrated into food packaging to monitor freshness (to reduce food waste and plastic pollution) or implemented into near-field-communication tags to function as wireless, battery-less gas sensors that can be interrogated with smartphones.
Printed electrical gas sensors are a low-cost, lightweight, low-power, and potentially disposable alternative to gas sensors manufactured using conventional methods such as photolithography, etching, ...and chemical vapor deposition. The growing interest in Internet-of-Things, smart homes, wearable devices, and point-of-need sensors has been the main driver fueling the development of new classes of printed electrical gas sensors. In this Perspective, we provide an insight into the current research related to printed electrical gas sensors including materials, methods of fabrication, and applications in monitoring food quality, air quality, diagnosis of diseases, and detection of hazardous gases. We further describe the challenges and future opportunities for this emerging technology.
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