Abstract

There is an emerging consensus that the future of intelligent and energy efficient homes is automation and cloud control. This paper presents a novel infrastructural concept using smart ceiling tiles and an energy-harvesting Bluetooth Low Energy (BLE) switch to control home appliances. The switch location is determined using trilateration of the signals received by the tiles installed in different rooms. In this paper, we localized the switch among three rooms separated by a brick wall by analyzing the received signal strength indicator (RSSI) values captured by three tiles located in three rooms. The tiles are powered with DC power using the support rails, thus minimizing wiring for power delivery. We used different machine learning classification algorithms with the received RSSI values as features for predicting the location of the switch accurately. Through experimentation, we achieved high accuracy of 93% in classifying the switch position among the rooms. The integration of smart tiles in the false ceiling along with the use of an energy-harvesting BLE switch offers numerous advantages, such as reducing wiring complexity, enhancing user convenience, and aesthetic design.

Abstract

Street lights are ubiquitous public infrastructure in urban areas that can be leveraged for smart city applications. In this paper, we present an electric vehicle charging station (EVCS) that communicates using Wi-SUN network integrated on a network of streetlights, and using oneM2M middleware. The proposed architecture follows the level 2 charging standards and the open charge point protocol (OCPP), ensuring compatibility and interoperability across diverse charging infrastructures. By seamlessly incorporating Wi-SUN network and oneM2M middleware, our architecture enables efficient communication and interaction with a wide array of devices and services. The utilization of the oneM2M platform further enhances the integration by establishing a seamless connection between the EVCS and the broader smart city infrastructure. We have fabricated a proof-of-concept system that consists of the EVCS connected to a Wi-SUN network integrated with the streetlight network in the institute campus. The performance of our solution was evaluated by measuring the latency associated with authentication and billing for EV users. We report the average latency observed over several iterations of charging to be 0.7±0.2 s (excluding the time required for charging). We also measured the Wi-SUN communication range in the campus environment with trees and buildings and found the maximum range to be around 370 m.

Abstract

Electrically conductive fibers are attracting attention because of the newly emerging areas of interactive textiles and smart fabrics. In this paper, we present the fabrication and characterization of a flexible conductive cotton fabric (CCF) of size 20 cm×20 cm coated with polypyrrole synthesized using in-situ chemical oxidative polymerization. This is the largest area reported in the literature for a polypyrrole-coated conducting fabric. The characteristics of the conducting fabric were investigated at 25 points by sandwiching it between the electrodes in the form of a 5×5 array. To test its reliability, the CCF was washed with distilled water 10 times, and its response was measured after every wash. We observed that there was a change in the resistance after the first four washes, however, the response stabilized thereafter. The average deviation in resistance until first four washes was found to be 27.45%, whereas for washes 6 to 10, it was 5.11%.

Abstract

A smart thermal patch for adaptive thermotherapy is provided. In an embodiment, the patch can be a stretchable, non-polymeric, conductive thin film flexible and non-invasive body integrated mobile thermal heater with wireless control capabilities that can be used to provide adaptive thermotherapy. The patch can be geometrically and spatially tunable on various pain locations. Adaptability allows the amount of heating to be tuned based on the temperature of the treated portion.

Abstract

Digital multimedia tools are becoming increasingly important as the world slowly shifts to an online mode. In this work, we present a low-cost, flexible writing pad that uses a 16×16 pressure sensing matrix based on the piezoresistive thin film of velostat. The writing area is 5 cm × 5 cm with an effective pixel area of 0.06 mm2 . A read out circuit is designed to detect the change in resistance of the velostat pixel using a voltage divider. A microprocessor raster scans through the sensor pixel matrix to obtain a data frame of 256 integers. This data is processed using techniques like squaring and normalising (S&N), Gaussian blurring, and adaptive thresholding to generate a more readable output. The writing pad is able to resolve characters larger than 2 cm in length. The flexible writing pad produces legible output while flexed at bending radius of upto 4 cm. Such flexibility promises to enhance the usability and portability of the writing pad significantly. Index Terms—Flexible PCB, Flexible writing pad, Piezoresistive material, Pressure sensor, Velostat

Abstract

Micropumps are one of the most widely used components in lab-on-a-chip devices and other biomedical applications as they can manipulate fluid flow in a very small footprint. In this study, a flexible nozzle-diffuser planar micropump was fabricated using polydimethylsiloxane (PDMS). The pump was fabricated using a two-layer structure: bottom layer with molded channels and chamber encapsulated by a planar top layer. The use of PDMS as the structural material for both layers imparts flexibility and transparency to the complete pump assembly. The micropump was characterized by counting the number of compression cycles required for a known volume of fluid, here water, to flow from the inlet to the outlet. A similar characterization was performed while bending the pump at bending radii of 71 cm and 45 cm. The pump produced a flow rate per compression cycle of 5.53 µl on flat surface and that of 4µl, 3.6 µl when placed on surfaces of bending radii of 71cm and 45 cm respectively. The transparency of the pump and biocompatability of PDMS make it an excellent material for biomedical and colorimetric applications.

Abstract

The continuous monitoring of maternal vital signs, particularly during labor, can be of critical importance for the health of the child and mother. We present a compact wearable electronic system that measures, in real-time, maternal heart rate using electrocardiography (ECG) signals. The heart rate is determined using moving average filters to remove the noises in the signal and using autocorrelation for the detection of periodic signals. We use electromyography (EMG) signals for calculating uterine contractions using the root mean sum of filtered signal values. The resulting system can identify heart rate in a female subject with an accuracy of ± 2.9bpm, and uterine contraction intensity within ± 5 units compared to values obtained from a gold-standard CTG machine. The system is accurate, low-cost, and portable, so that it can be deployed at primary healthcare centers in low-income countries. The system can also be

Abstract

Plantar pressure or foot pressure analysis is a predominant tool for biomedical assessment of posture, gait, and other activities. The distribution and magnitude of pressure can provide fruitful information to diagnose or predict any risk of foot disorders or impairments. This paper presents the design and fabrication of a low-cost, flexible pressure sensor (FLEPS) mat for assessing plantar pressure variations. We have designed a 32 × 32 velostat-based piezoresistive pressure sensor array with dimensions of 330 mm × 330 mm and an active sensing area of 284 mm × 284 mm. Each sensor pixel is of size 5 mm × 5 mm with a pitch of 4 mm. To enhance the resolution and the visual quality of the heat map obtained, we have used different interpolation techniques like the nearest neighbor, bilinear, and bicubic for the received data and transformed the 32 × 32 array to a 100 × 100-pixel array. It was observed that the bicubic interpolation technique gives a better image quality but takes more computation time than the other two interpolation techniques. Index Terms—Flexible pressure sensor, Interpolation, Piezore- sistive, Plantar pressure, Velostat.

Abstract

The scalability of remote Internet of Things (IoT) deployments into verticals of smart cities relies primarily on the communication protocols and data platforms employed. Accordingly, the adoption of LoRaWAN, Sigfox, NB-IoT, etc. has risen in recent years. These protocols have been created to cater to the low power and long range requirements of IoT. In this paper, we evaluate one such protocol, Wi-SUN (Wireless Smart Ubiquitous Network), that additionally offers excellent redundancy owing to its use of a mesh topology. Wi-SUN is based on the IEEE 802.15.4g standard and uses license-free sub-GHz bands. However, IoT networks using any communication protocol require a knowledge of signal propagation and attenuation in real-world scenarios. Thus, we evaluated the path loss of Wi- SUN transmissions by analysing the RSSI values inside a typical city building and an urban outdoor habitat. Keywords—Path Loss,

Abstract

PP10. 00010: Structural engineering methods to combine the diaphragm and cantilevers for flexible capacitive pressure sensor*