Abstract

Various examples are provided for stretchable antennas that can be used for applications such as wearable electronics. In one example, a stretchable antenna includes a flexible support structure including a lateral spring section having a proximal end and at a distal end; a metallic antenna disposed on at least a portion of the lateral spring section, the metallic antenna extending along the lateral spring section from the proximal end; and a metallic feed coupled to the metallic antenna at the proximal end of the lateral spring section. In another example, a method includes patterning a polymer layer disposed on a substrate to define a lateral spring section; disposing a metal layer on at least a portion of the lateral spring section, the metal layer forming an antenna extending along the portion of the lateral spring section; and releasing the polymer layer and the metal layer from the substrate.

Abstract

A sensor system includes at least one sensor configured to detect at least one environmental parameter, a processor coupled to the at least one sensor, and a dissolvable polymer encasing the sensor system.

Abstract

Cantilevers are one of the most utilized mechanical elements for acoustic sensing. In comparison to the edge clamped diaphragms of different shapes, a single edge clamped cantilever makes an acoustic sensor mechanically sensitive for detection of lower pressure. The aspect ratio of cantilevers is one of the most important parameters which affect sensitivity. Herein, we present a mathematical, finite element method and experimental analysis to determine the effect of the aspect ratio on the resonant frequency, response time, mechanical sensitivity, and capacitive sensitivity of a cantilever-based acoustic pressure sensor. Three cantilevers of different aspect ratios (0.67, 1, and 1.5) have been chosen for sound pressure application to detect capacitance change. The cantilever with the smallest aspect ratio (0.67) has the highest response time (206 ms), mechanical sensitivity, and capacitive sensitivity (22 fF), which …

Abstract

Capacitive pressure sensors have several advantages in areas such as robotics, automation, aerospace, biomedical and consumer electronics. We present mathematical modelling, finite element analysis (FEA), fabrication and experimental characterization of ultra-low cost and paper-based, touch-mode, flexible capacitive pressure sensor element using Do-It-Yourself (DIY) technology. The pressure sensing element is utilized to design large-area electronics skin for low-cost prosthetic hands. The presented sensor is characterized in normal, transition, touch and saturation modes. The sensor has higher sensitivity and linearity in touch mode operation from 10 to 40 kPa of applied pressure compared to the normal (0 to 8 kPa), transition (8 to 10 kPa) and saturation mode (after 40 kPa) with response time of 15.85 ms. Advantages of the presented sensor are higher sensitivity, linear response, less diaphragm area …

Abstract

A method for producing a semiconductor device involves forming a first transistor having a silicon substrate and a gate, and forming a second transistor, having a germanium substrate, on top of the first transistor. The second transistor is formed by forming a first gate of the second transistor on top of, and electrically coupled to, the gate of the first transistor, bonding the germanium substrate to the first gate of the second transistor so that the bonding does not damage the first transistor, and forming a second gate of the second transistor on the germanium substrate.

Abstract

Current air pollution monitoring systems are bulky and expensive resulting in a very sparse deployment. In addition, the data from these monitoring stations may not be easily accessible. This paper focuses on studying the dense deployment based air pollution monitoring using IoT enabled low-cost sensor nodes. For this, total nine low-cost IoT nodes monitoring particulate matter (PM), which is one of the most dominant pollutants, are deployed in a small educational campus in Indian city of Hyderabad. Out of these, eight IoT nodes were developed at IIIT-H while one was bought off the shelf. A web based dashboard website is developed to easily monitor the real-time PM values. The data is collected from these nodes for more than five months. Different analyses such as correlation and spatial interpolation are done on the data to understand efficacy of dense deployment in better understanding the spatial variability and time-dependent changes to the local pollution indicators.

Abstract

Energy consumption has dramatically increased in the residential building sector over the past few years. Many researchers today are interested not only in designing energy-efficient buildings but also in evaluating the actual building performance and managing operations for delivering the design intent. Monitoring building performance using currently available sensors and mobile applications poses challenges in terms of cost and standardization. This paper presents a new approach to make sensors affordable and inter-operable by designing open-source hardware and using well-established standards for data communication and storage, thereby making energy monitoring ubiquitous and affordable in the residential sector. The proposed solution uses low-power loggers, Bluetooth Low Energy wireless communication version 4 for data transfer from loggers to mobile phones for further transfer to cloud, oneM2M standard to ensure interoperability, and NGSI-LD for data management.

Abstract

Micropumps are one of the most important parts of a microfluidic system. In particular, for biomedical applications such as Lab-on-Chip systems, micropumps are used to transport and manipulate test fluids in a controlled manner. In this paper, a low-cost, structurally simple, piezoelectrically actuated micropump was simulated and fabricated using poly-dimethylsiloxane (PDMS). The channels in PDMS were fabricated using patterned SU-8 structures. The pump flow rate was measured to be 9.49 μL/min, 14.06 μL/min and 20.87 μL/min for applied voltages of 12 V, 14 V and 16 V respectively. Further, we report finite element analysis (FEA) simulation to confirm the operation of the micropump and compare favorably the experimentally obtained flowrate with the one predicted by simulation. By taking these flow rates as a reference, the chamber pressure was found to be 1.1 to 1.5 kPa from FEA simulations.

Abstract

With recent advancements in the field of wearable devices based on Internet of Things (IoT), the concept of flexible and stretchable electronic systems has become increasingly significant. Although decades of dimensional scaling have led to the miniaturization of the traditional complementary metal oxide semiconductor-(CMOS-) based electronic components, they still remain mechanically rigid and brittle. These rigid devices can be mounted on flexible PCB substrates to obtain a certain degree of flexibility; however, this technique cannot lead to truly body conformal electronic systems. Thus, research teams around the world have been looking at various ways of obtaining completely flexible electronic components at the device level itself. These efforts include various processes to thin down silicon chips to make them flexible or development and use of flexible and stretchable substrate materials to fabricate electronic devices. The thinning down process for traditional silicon-based electronic chips can be performed before or after the complete transistor fabrication process [1]. These approaches are referred to as “device first” approach or “device last” approach. In case of the device last approach, thin films of single crystal silicon are transfer printed to a flexible substrate and processed further to fabricate CMOS circuitry [2, 3]. However, in this approach, many high-temperature steps have to be avoided due to the limited thermal stability of the flexible substrate, leading to a suboptimal circuit. In case of the device first approach, the circuits are made on the silicon substrate using state-of-the-art CMOS processes as usual. After completion of the …

Abstract

A capacitive pressure sensor consists of a movable diaphragm which causes change in capacitance for an applied pressure. In order to achieve high sensitivity, a thin diaphragm of large area is employed with a small separation gap. This introduces non-linearity, decreases the dynamic range and increases the size of the sensor. Thus, an optimum sensor design is necessary to balance these trade-offs. This paper presents theoretical modeling and numerical simulations on various performance parameters like diaphragm deflection, change in capacitance, mechanical and capacitive sensitivities and nonlinearity of a clamped and normal mode elliptical capacitive pressure sensor for 0 – 8 kPa operating pressure range. This analysis can form the basis for compact modelling (CM) of circular and elliptical capacitive pressure sensors for simulation with large scale circuits. In all the designs of elliptical and circular …