Low-power Wearable Healthcare Sensors

Advances in technology have produced a range of on-body sensors and smartwatches that can be used to monitor a wearer’s health with the objective to keep the user healthy. However, the real potential of such devices not only lies in monitoring but also in interactive communication with expert-system-based cloud services to offer personalized and real-time healthcare advice that will enable the user to manage their health and, over time, to reduce expensive hospital admissions. To meet this goal, the research challenges for the next generation of wearable healthcare devices include the need to offer a wide range of sensing, computing, communication, and human–computer interaction methods, all within a tiny device with limited resources and electrical power. This Special Issue presents a collection of six papers on a wide range of research developments that highlight the specific challenges in creating the next generation of low-power wearable healthcare sensors

Skin-Integrated wearable systems and implantable biosensors: a comprehensive review

Biosensors devices have attracted the attention of many researchers across the world. They have the capability to solve a large number of analytical problems and challenges. They are future ubiquitous devices for disease diagnosis, monitoring, treatment and health management. This review presents an overview of the biosensors field, highlighting the current research and development of bio-integrated and implanted biosensors. These devices are micro- and nano-fabricated, according to numerous techniques that are adapted in order to offer a suitable mechanical match of the biosensor to the surrounding tissue, and therefore decrease the body’s biological response. For this, most of the skin-integrated and implanted biosensors use a polymer layer as a versatile and flexible structural support, combined with a functional/active material, to generate, transmit and process the obtained signal. A few challenging issues of implantable biosensor devices, as well as strategies to overcome them, are also discussed in this review, including biological response, power supply, and data communication.This research was funded by FCT- FUNDAÇÃO PARA A CIÊNCIA E TECNOLOGIA, grant numbers: PTDC/EMD-EMD/31590/2017 and PTDC/BTM-ORG/28168/2017

Electrochemical Plug-and-Power e-readers for Point-of-Care Applications

Point-of-Care diagnostic tests enable monitor health conditions and obtain fast results close to the patient, reducing medical costs, and allowing the control of infectious outbreaks. The interest in developing Point-of-Care devices is increasing due to they are suitable for a wide variety of applications. This doctoral thesis focuses on the development of Plug-and-Power electronic readers (e- readers) for electrochemical detections and the demonstration of their possibilities as Point-of-Care diagnostic testing. The solutions proposed in this study make it possible to improve Point-of-Care tests whose premises are laboratory decentralization, personalized medicine, rapid diagnosis, and improvement of patient care. Developed electronic readers can be powered from a conventional system, such as a USB port or a lithium battery, or can be defined as self-powered systems, capable of extracting energy from alternative energy sources, such as fuel cells, defining Plug-and-Power systems. The designed electrochemical detection devices in this thesis are based on low-power consumption electronic instrumentation circuits. These circuits are capable of controlling the sensing element, measuring its response, and representing the result quantitatively. The implemented devices can work with both electrochemical sensors and fuel cells. Furthermore, it is possible to adapt its measurement range, enabling its use in a wide variety of applications. Thanks to their reduced energy consumption, some of these developments can be defined as self-powered platforms able to operate only with the energy extracted from the biological sample, which in turn is monitored. These devices are easy-to-use and plug-and-play, enabling those unskilled individuals to carry out tests after prior training. Moreover, thanks to their user-friendly interface, results are clear and easy to understand. This doctoral dissertation is presented as an article compendium and composed of three publications detailed in chronological order of publication. The first contribution describes an innovative portable Point-of-Care device able to provide a quantitative result of the glucose concentration of a sample. The proposed system combines an e-reader and a disposable device based on two elements: a glucose paper-based power source, and a glucose fuel cell-based sensor. The battery-less e-reader extracts the energy from the disposable unit, acquires the signal, processes it, and shows the glucose concentration on a numerical display. Due to low-power consumption of the e-reader, the whole electronic system can operate only with the energy extracted from the disposable element. Furthermore, the proposed system minimizes the user interaction, which only must deposit the sample on the strip and wait a few seconds to see the test result. The second publication validates the e-reader in other scenarios following two approaches: using fuel cells as a power element, and as a dual powering and sensing element. The device was tested with glucose, urine, methanol, and ethanol fuel cells and electrochemical sensors in order to show the adaptability of this versatile concept to a wide variety of fields beyond clinical diagnostics, such as veterinary or environmental fields. The third study presents a low-cost, miniaturized, and customizable electronic reader for amperometric detections. The USB-powered portable device is composed of a full- custom electronic board for signal acquisition, and software, which controls the systems, represents and saves the results. In this study, the performance of the device was compared against three commercial potentiostats, showing comparable results to those obtained using three commercial systems, which were significantly more expensive. As proof of concept, the system was validated by detecting horseradish peroxidase samples. However, it could be easily extended its scope and measure other types of analytes or biological matrices since it can be easily adapted to detect currents a wide range of currents.Las pruebas de diagnostico Point-of-Care permiten monitorizar las condiciones de salud y obtener resultados rápidos cerca del paciente, reduciendo los costes médicos y permitiendo controlar brotes infecciosos. El interés por desarrollar dispositivos de Point- of-Care está aumentando debido a que son aplicables a una amplia variedad de aplicaciones. Esta tesis doctoral se centra en el desarrollo de lectores electrónicos (e-readers) Plug-and- Power para detecciones electroquímicas y la demostración de sus posibilidades como pruebas de diagnóstico de punto de atención (Point-of-Care). Las soluciones propuestas en este trabajo permiten mejorar las pruebas Point-of-Care, cuyas premisas son la descentralización de laboratorio, la medicina personalizada, el diagnóstico rápido y la mejora de la atención al paciente. Los lectores electrónicos desarrollados pueden ser alimentados desde un sistema convencional, como puede ser un puerto USB o una batería de litio, o definirse como sistemas autoalimentados, capaces de extraen energía de fuentes alternativas de energía, como celdas de combustible (fuel cells), definiendo así sistemas Plug-and-Power. Los dispositivos de detección electroquímica diseñados se basan en circuitos de instrumentación electrónica de bajo consumo. Estos circuitos son capaces controlar el elemento de sensado, medir su respuesta y representar el resultado de forma cuantitativa. Los dispositivos implementados pueden trabajar tanto con sensores electroquímicos como con fuel cells. Además, es posible adaptar su rango de medida, permitiendo su utilización en una amplia variedad de aplicaciones. Gracias a su reducido consumo de energía, algunos de estos desarrollos pueden definirse como plataformas autoalimentadas capaces de operar solo con la energía extraída de la muestra biológica, que a su vez es monitorizada. Estas plataformas electrónicas son fáciles de usar y Plug-and-Play, permitiendo que personas no cualificadas puedan utilizarlas después de un previo entrenamiento. Además, gracias a su interfaz fácil de usar, los resultados son claros y fáciles de interpretar

Intelligent Circuits and Systems

ICICS-2020 is the third conference initiated by the School of Electronics and Electrical Engineering at Lovely Professional University that explored recent innovations of researchers working for the development of smart and green technologies in the fields of Energy, Electronics, Communications, Computers, and Control. ICICS provides innovators to identify new opportunities for the social and economic benefits of society.　 This conference bridges the gap between academics and R&D institutions, social visionaries, and experts from all strata of society to present their ongoing research activities and foster research relations between them. It provides opportunities for the exchange of new ideas, applications, and experiences in the field of smart technologies and finding global partners for future collaboration. The ICICS-2020 was conducted in two broad categories, Intelligent Circuits & Intelligent Systems and Emerging Technologies in Electrical Engineering

Electrospun piezoelectric polymer 3D structures for wearable energy harvesters

Wearable devices have emerged as one of the most rapidly growing branches of the consumer electronics industry in recent years. Having a wide breadth of applications, ranging from leisure and fitness tracking to therapeutics and diagnostics, their development has become a critical driving force in the field of personalised medicine and point-of-care technologies. With the availability of more powerful processing techniques, efficient design approaches, and the miniaturisation of the basic building blocks that conform them, the capabilities of wearable devices have great potential for growth. Energy sources are one of the critical challenges associated with the design of wearable electronics. Renewable sources such as piezoelectric energy harvesters are of great interest, offering a viable alternative that can help tackle the problem of e-waste by enhancing the lifespan of a primary power source or as an independent power source. The piezoelectric active core materials of energy harvesters are the elements that allow for the conversion of mechanical energy to electrical energy. Contrary to the case of using piezoelectric ceramics, polymer based active cores offer superior flexibility, low manufacturing costs, and are non-toxic. However, their piezoelectric properties are comparatively lower than those of ceramics. Micro and nanofabrication methods for the manufacture of polymer based piezoelectric structures are of great interest in the field of energy harvesting because they allow for the tuning of specific morphological properties of these materials, offering the possibility of tailoring the material to the intended application and for the enhancement of the piezoelectric properties of the manufactured structures in some cases, which can bring the piezoelectric performance of polymer based materials closer to that of ceramics Electrospinning is a technique for the fabrication of nano and microfibrous structures based on the principles of electrohydrodynamics. This versatile manufacturing method not only allows for the fabrication of diverse morphologies of a material depending on the working parameters, ambient conditions and reagents, but can also intrinsically enhance the properties of the product. In this thesis, electrospinning will be used for the fabrication of polymer based piezoelectric materials. The work presented in the following chapters will focus firstly on the optimisation of the working parameters and on the composition of the polymer solutions for the fabrication of morphologically stable fibres and consequently will deal with improving the electrical response of these structures when they are used as the active core of a piezoelectric generator. Initial experimental work deals with the optimisation of polymer solutions containing the ferroelectric polymer poly(vinylidene fluoride) (PVDF). Favourable conditions for the fabrication of PVDF nanofibres were identified, and the resulting 2D fibrous mats were used for assembling a first iteration of piezoelectric generators. The findings indicated that the electrospun PVDF product had a favourable electrical response in spite of the morphology of the fibrous product not being ideal. Thus, improving the quality of the electrospun products would certainly allow for the fabrication of better performing generators. The use of chemical additives, solvent systems, and the combination of polymers for electrospinning can heavily influence the quality of the product. This thesis proceeds with the exploration of this premise, using combinations of PVDF with poly(ethylene oxide) (PEO) and lithium chloride (LiCl) for improving the quality of the material. Fibre morphology improved dramatically with the use of these additives, and it was observed that the fabricated fibrous structures could now transition to 3D materials under specific conditions, with variants ranging from a cloud-like structure to thick sponge-like fibrous mats. The conditions required for the production of 3D structures were found to be compatible with poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE), a copolymer known to have intrinsically superior piezoelectric properties than PVDF. The fabricated structures were used for assembling piezoelectric generators, and their electrical properties were shown to be comparable or to outperform similar state-of-the-art devices. Design opportunities were identified while working on the proposed piezoelectric generator architecture and the interfacing methods used for bonding the active core to the electrode materials. The thesis finalises with an exploration of additional methods that can be used to further increase the electrical response of generators with thick sponge-like fibrous PVDF-TrFE/PEO active cores. The findings of this final study revealed that electrode placement and design that conforms to the characteristics of the electrospun fibrous core and the use of electrode materials that can interface with both the surface of the active core and the fibrous network within the core material can improve the electrical output of the generators dramatically. The multidisciplinary work presented in this thesis explored fields ranging from chemistry and materials science to electronics and electrical engineering, laying the ground work upon which new research opportunities for the development of portable renewable energy sources can develop

WOFEX 2021 : 19th annual workshop, Ostrava, 1th September 2021 : proceedings of papers

The workshop WOFEX 2021 (PhD workshop of Faculty of Electrical Engineer-ing and Computer Science) was held on September 1st September 2021 at the VSB – Technical University of Ostrava. The workshop offers an opportunity for students to meet and share their research experiences, to discover commonalities in research and studentship, and to foster a collaborative environment for joint problem solving. PhD students are encouraged to attend in order to ensure a broad, unconfined discussion. In that view, this workshop is intended for students and researchers of this faculty offering opportunities to meet new colleagues.Ostrav