Sensing Movement: Microsensors for Body Motion Measurement

Recognition of body posture and motion is an important physiological function that can keep the body in balance. Man-made motion sensors have also been widely applied for a broad array of biomedical applications including diagnosis of balance disorders and evaluation of energy expenditure. This paper reviews the state-of-the-art sensing components utilized for body motion measurement. The anatomy and working principles of a natural body motion sensor, the human vestibular system, are first described. Various man-made inertial sensors are then elaborated based on their distinctive sensing mechanisms. In particular, both the conventional solid-state motion sensors and the emerging non solid-state motion sensors are depicted. With their lower cost and increased intelligence, man-made motion sensors are expected to play an increasingly important role in biomedical systems for basic research as well as clinical diagnostics

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

Modelling and Design Optimisations of CMOS MEMS Single Membrane Thermopile Detector Arrays

Thermal imaging devices based on Complementary Metal-Oxide-Semiconductor (CMOS) and Micro-Electro-Mechanical System (MEMS) technology are widely used across consumer and industrial applications. The combination of CMOS and MEMS technologies allows for the production of devices with high performance, good reliability and consistent reproducibility. Additionally, these technologies allow devices to be manufactured at low cost and a high volume. There are several types of thermal sensing technologies, however, this thesis mainly focuses on 8×8 thermopile based Focal Plane Arrays (FPAs). The core principles governing the function of thermopiles are based on the Seebeck effect. In this thesis, the structure and fabrication process of thermopile FPAs are described and discussed. The thesis describes the functionality of the array chip and introduces a new experimental technique, called the bi-directional electrical biasing method, which was applied to obtain the device’s responsivity and crosstalk measurements. Compared to traditional measurement approaches using laser sources, this novel method significantly reduces the complexity of the experimental setup, as no external laser source is required. The crosstalk of the 8×8 array is ~2.69% and the responsivity is ~73.1 V/W. A detecting system using a larger array chip was designed, created and successfully applied in a series of experiments that involved gesture recognition and people counting. In order to enhance the performance of the current array device, a 3D simulation model based on the Finite Element Method (FEM) was built using the COMSOL Multiphysics simulation tool. The numerical model was validated by comparing the model’s simulated values for responsivity, crosstalk and temperature distribution with experimental results. The difference between the simulations and experimental results was 90 V/W in the model with tungsten tracks. A 32×32 array design demonstrates the smallest pixel size that can be achieved based on this thermopile array design. The 32×32 array design increased responsivity to ~77.18 V/W and crosstalk remained 6% when the pixel size was reduced further in a 64×64 array design, at this level of crosstalk, image quality is likely to be significantly affected. Future work may focus on the implementation of carbon nanotubes or novel 3D thermopile designs. Carbon nanotubes, when deposited over the array chip, could enhance the absorption of IR radiation. While new thermopiles employing a 3D design could dramatically reduce array size and potentially achieve a fill factor of 100%

An inclusive survey of contactless wireless sensing: a technology used for remotely monitoring vital signs has the potential to combating COVID-19

With the Coronavirus pandemic showing no signs of abating, companies and governments around the world are spending millions of dollars to develop contactless sensor technologies that minimize the need for physical interactions between the patient and healthcare providers. As a result, healthcare research studies are rapidly progressing towards discovering innovative contactless technologies, especially for infants and elderly people who are suffering from chronic diseases that require continuous, real-time control, and monitoring. The fusion between sensing technology and wireless communication has emerged as a strong research candidate choice because wearing sensor devices is not desirable by patients as they cause anxiety and discomfort. Furthermore, physical contact exacerbates the spread of contagious diseases which may lead to catastrophic consequences. For this reason, research has gone towards sensor-less or contactless technology, through sending wireless signals, then analyzing and processing the reflected signals using special techniques such as frequency modulated continuous wave (FMCW) or channel state information (CSI). Therefore, it becomes easy to monitor and measure the subject’s vital signs remotely without physical contact or asking them to wear sensor devices. In this paper, we overview and explore state-of-the-art research in the field of contactless sensor technology in medicine, where we explain, summarize, and classify a plethora of contactless sensor technologies and techniques with the highest impact on contactless healthcare. Moreover, we overview the enabling hardware technologies as well as discuss the main challenges faced by these systems.This work is funded by the scientific and technological research council of Turkey (TÜBITAK) under grand 119E39

MEMS Accelerometers

Micro-electro-mechanical system (MEMS) devices are widely used for inertia, pressure, and ultrasound sensing applications. Research on integrated MEMS technology has undergone extensive development driven by the requirements of a compact footprint, low cost, and increased functionality. Accelerometers are among the most widely used sensors implemented in MEMS technology. MEMS accelerometers are showing a growing presence in almost all industries ranging from automotive to medical. A traditional MEMS accelerometer employs a proof mass suspended to springs, which displaces in response to an external acceleration. A single proof mass can be used for one- or multi-axis sensing. A variety of transduction mechanisms have been used to detect the displacement. They include capacitive, piezoelectric, thermal, tunneling, and optical mechanisms. Capacitive accelerometers are widely used due to their DC measurement interface, thermal stability, reliability, and low cost. However, they are sensitive to electromagnetic field interferences and have poor performance for high-end applications (e.g., precise attitude control for the satellite). Over the past three decades, steady progress has been made in the area of optical accelerometers for high-performance and high-sensitivity applications but several challenges are still to be tackled by researchers and engineers to fully realize opto-mechanical accelerometers, such as chip-scale integration, scaling, low bandwidth, etc

Elderly Assist Robot

This project aimed to create a robot capable of assisting elderly people with tasks in their everyday lives. The project focused on the design, simulation, and the implementation of a mobile robotic base with an attached robotic arm. The project culminated in a prototype robot capable of performing basic chassis and arm control which can be used as a platform for future development