Wireless colorimetric readout to enable resource-limited point-of-care

Patientennahe Diagnostik in Entwicklungsländer birgt spezielle Herausforderungen, die ihren Erfolg bisher begrenzen. Diese Arbeit widmet sich daher der Entwicklung eines in seiner Herstellung skalierbaren und vielseitig einsetzbaren funkbasierten Auslesegerätes für Laborteststreifen. Durch die Kombination einer wachsenden Auswahl an papierbasierten Teststreifendiagnostiken mit gedruckter Elektronik und unter Berücksichtigung des diagnostischen Alltags im südlichen Afrika wurde ein Gerät entwickelt, das Teststreifen zuverlässig ausliest und die Daten per Funk an eine Datenbank übertragen kann. Die Technik basiert auf RFID-Tags (radio frequency identification devices), welche auf verschiedene flexible Substrate gedruckt wurden, um die technische Umsetzbarkeit und Funktionalität zu evaluieren. Um den Preis für die geplante Anwendung niedrig zu halten, wurden unter anderem Papier und Karton als Substrate genutzt. Das Ergebnis dieser Studie sind passive RFID-Tags auf unterschiedlichen, meist günstigen Substraten, die über eine Distanz von über 75 mm betrieben und ausgelesen werden können. Basierend auf der über RFID bereitgestellten Energie und Datenübertragung wurde eine Ausleseeinheit für Standardpapierstreifentests entwickelt und integriert. Durch das Auslesen verschiedener Teststreifen wurde das Gerät evaluiert und in seiner Aussagekraft mit einer scanner-basierten Aufnahme und anschließender Bildanalyse (ImageJ), einem kommerziellen Auslesegerät sowie einer manuellen Auslesung mit Hilfe von Farbtabellen verglichen. Das Gerät kann die Streifen zuverlässig auslesen und die Daten über die RFID-Schnittstelle übertragen. Die funkbasierte Ausleseeinheit ist mit verschiedenen kommerziellen Teststreifen sowohl im biodiagnostischen (lateral flow tests) wie auch im chemischen Bereich (pH-Wert) kompatibel. Die modulare Lösung erlaubt ein breites Einsatzgebiet und führt dadurch zu reduzierten Trainingszeiten der Anwender und einer zuverlässigen Handhabung. Die vorgestellte Lösung ist äußerst kostengünstig und bedarf keiner Wartung, wodurch sie sich sehr gut für den Einsatz in abgelegenen Feldkrankenhäusern eignet. Es wurde ein skalierbarer Prototyp entwickelt, der auf konventionellen Herstellungsverfahren der Verpackungsindustrie aufbaut. Aktuell handelt es sich noch um einen bogenbasierten Prozess, der sich aber prinzipiell auch auf Rolle-zu-Rolle Maschinen übertragen lässt. Bei der Entwicklung des Geräts spielte die Möglichkeit der lokalen Herstellung in den Einsatzländern eine große Rolle. Diese hätte neben der Generierung von Arbeitsplätzen auch den Vorteil einer einfacheren Verteilung der Geräte in ländliche Regionen, in denen sie den größten Nutzen für die Diagnostik erzielen würden

Passive UHF RFID Tag with Multiple Sensing Capabilities

This work presents the design, fabrication, and characterization of a printed radio frequency identification tag in the ultra-high frequency band with multiple sensing capabilities. This passive tag is directly screen printed on a cardboard box with the aim of monitoring the packaging conditions during the different stages of the supply chain. This tag includes a commercial force sensor and a printed opening detector. Hence, the force applied to the package can be measured as well as the opening of the box can be detected. The architecture presented is a passive single-chip RFID tag. An electronic switch has been implemented to be able to measure both sensor magnitudes in the same access without including a microcontroller or battery. Moreover, the chip used here integrates a temperature sensor and, therefore, this tag provides three different parameters in every reading.This work was partially funded by the Ministerio de Educación y Ciencia under Projects CTQ2009-14428-C02-01 and CTQ2009-14428-C02-02 and the Junta de Andalucía (Proyecto de Excelencia P10-TIC-5997), Spain. This project was partially supported by European Regional Development Funds (ERDF)

Critical Management Issues for Implementing RFID in Supply Chain Management

The benefits of radio frequency identification (RFID) technology in the supply chain are fairly compelling. It has the potential to revolutionise the efficiency, accuracy and security of the supply chain with significant impact on overall profitability. A number of companies are actively involved in testing and adopting this technology. It is estimated that the market for RFID products and services will increase significantly in the next few years. Despite this trend, there are major impediments to RFID adoption in supply chain. While RFID systems have been around for several decades, the technology for supply chain management is still emerging. We describe many of the challenges, setbacks and barriers facing RFID implementations in supply chains, discuss the critical issues for management and offer some suggestions. In the process, we take an in-depth look at cost, technology, standards, privacy and security and business process reengineering related issues surrounding RFID technology in supply chains

Technological Integration in Printed Electronics

Conventional electronics requires the use of numerous deposition techniques (e.g. chemical vapor deposition, physical vapor deposition, and photolithography) with demanding conditions like ultra-high vacuum, elevated temperature and clean room facilities. In the last decades, printed electronics (PE) has proved the use of standard printing techniques to develop electronic devices with new features such as, large area fabrication, mechanical flexibility, environmental friendliness and—potentially—cost effectiveness. This kind of devices is especially interesting for the popular concept of the Internet of Things (IoT), in which the number of employed electronic devices increases massively. Because of this trend, the cost and environmental impact are gradually becoming a substantial issue. One of the main technological barriers to overcome for PE to be a real competitor in this context, however, is the integration of these non-conventional techniques between each other and the embedding of these devices in standard electronics. This chapter summarizes the advances made in this direction, focusing on the use of different techniques in one process flow and the integration of printed electronics with conventional systems

Flexible Passive NFC Tag for Multi-Gas Sensing

In this work we present a full-passive flexible multigas sensing tag for the determination of oxygen, carbon dioxide, ammonia, and relative humidity readable by a smartphone. This tag is based on near field communication (NFC) technology for energy harvesting and data transmission to a smartphone. The gas sensors show an optic response that is read through high-resolution digital color detectors. A white LED is used as the common optical excitation source for all the sensors. Only a reduced electronics with very low power consumption is required for the reading of the optical responses and data transmission to a remote user. An application for the Android operating system has been developed for the power supplying and data reception from the tag. The responses of the sensors have been calibrated and fitted to simple functions, allowing a fast prediction of the gases concentration. Cross-sensitivity has also been evaluated, finding that in most of the cases it is negligible or easily correctable using the rest of the readings. The election of the target gases has been due to their importance in the monitoring of modified atmosphere packaging. The resolutions and limits of detection measured are suitable for such kinds of applications.This work was supported by project CTQ2013-44545-R from the Ministry of Economy and Competitiveness (Spain) and Junta de Andalucía (Proyecto de Excelencia P10- FQM-5974). These projects were partially supported by European Regional Development Funds (ERDF). P. Escobedo wants to thank the Spanish Ministry of Education, Culture and Sport (MECD) for a pre-doctoral grant (FPU13/05032)

Passive UHF RFID Tag for Multispectral Assessmen

This work presents the design, fabrication, and characterization of a passive printed radiofrequency identification tag in the ultra-high-frequency band with multiple optical sensing capabilities. This tag includes five photodiodes to cover a wide spectral range from near-infrared to visible and ultraviolet spectral regions. The tag antenna and circuit connections have been screen-printed on a flexible polymeric substrate. An ultra-low-power microcontroller-based switch has been included to measure the five magnitudes issuing from the optical sensors, providing a spectral fingerprint of the incident electromagnetic radiation from ultraviolet to infrared, without requiring energy from a battery. The normalization procedure has been designed applying illuminants, and the entire system was tested by measuring cards from a colour chart and sensing fruit ripening

Microwave Devices for Wearable Sensors and IoT

The Internet of Things (IoT) paradigm is currently highly demanded in multiple scenarios and in particular plays an important role in solving medical-related challenges. RF and microwave technologies, coupled with wireless energy transfer, are interesting candidates because of their inherent contactless spectrometric capabilities and for the wireless transmission of sensing data. This article reviews some recent achievements in the field of wearable sensors, highlighting the benefits that these solutions introduce in operative contexts, such as indoor localization and microwave sensing. Wireless power transfer is an essential requirement to be fulfilled to allow these sensors to be not only wearable but also compact and lightweight while avoiding bulky batteries. Flexible materials and 3D printing polymers, as well as daily garments, are widely exploited within the presented solutions, allowing comfort and wearability without renouncing the robustness and reliability of the built-in wearable sensor

UHF Printed Sensor for Force Detection

In this contribution, we show the advances in the direction of designing Radiofrequency Identification (RFID) antennas with sensing capabilities. In this particular case, we have integrated a force/pressure sensor made of a silicon-based organic polymer in one of the arms of a dipole antenna made of silver paste. The sensor response to external forces modifies the resonance frequency of the dipole antenna that can be detected by an external RFID reader, building up a wireless force sensor system.Pervasive Electronics Advanced Research Laboratory(PEARL), Department of Electronics and Computer Technology, University of Granada Institute for Nanoelectronics, Technical University of Munic

Wearable sensors for respiration monitoring: a review

This paper provides an overview of flexible and wearable respiration sensors with emphasis on their significance in healthcare applications. The paper classifies these sensors based on their operating frequency distinguishing between high-frequency sensors, which operate above 10 MHz, and low-frequency sensors, which operate below this level. The operating principles of breathing sensors as well as the materials and fabrication techniques employed in their design are addressed. The existing research highlights the need for robust and flexible materials to enable the development of reliable and comfortable sensors. Finally, the paper presents potential research directions and proposes research challenges in the field of flexible and wearable respiration sensors. By identifying emerging trends and gaps in knowledge, this review can encourage further advancements and innovation in the rapidly evolving domain of flexible and wearable sensors.This work was supported by the Spanish Government (MICINN) under Projects TED2021-131209B-I00 and PID2021-124288OB-I00.Peer ReviewedPostprint (published version