Anindya Nag

Occupancy Detection at Smart Home Using Real-Time Dynamic Thresholding of Flexiforce Sensor

Monitoring of the activities of the occupant is paramount important in the field of ambient-assisted living environment. Sensors are widely used to collect, store, and analyze on the continuous stream of data of the observation of their day-to-day activities. The output of any sensor may gradually change with time. It may come to a point where it becomes difficult to make a distinction between different situations from the sensors output. Due to the change of sensors output with time, it is hard for the system to discriminate very accurately between the regular states and the irregular states. This paper deals with the problems faced with the output of flexiforce sensors that happens when the sensor is in operation for a long period to monitor the activities of the inhabitant. A real-time dynamic thresholding has been designed and introduced to identify different situations clearly and avoid confusions regarding the output of the sensor used.

Novel Sensing Approach for LPG Leakage Detection—Part II: Effects of Particle Size, Composition, and Coating Layer Thickness

Prominent research has been going on to develop a low-cost, efficient gas sensing system. This paper presents a continuation of our earlier research work done to develop a new sensing approach for gas detection at ambient conditions. This paper exhibits the optimization of the response time of the sensor by inhabiting characteristic changes such as variation in the concentration of the dispersion medium, thickness of the coating, and the size of the dispersed medium. Different concentrations of the dispersion medium in the coated suspension were tested to determine the optimal composition required to achieve the highest sensitivity of the tin oxide (SnO2) layer toward the tested gas. The control over adsorption and desorption of the gas molecules in the coated layer was achieved by investigating the particle size of the dispersed medium. The response time of the coated sensor was encouraging and owns a promising potential to the development of a more efficient gas sensing system.

Novel Sensing Approach for LPG Leakage Detection: Part I—Operating Mechanism and Preliminary Results

Gas sensing technology has been among the topical research work for quite some time. This paper showcases the research done on the detection mechanism of leakage of domestic cooking gas at ambient conditions. Micro-electro mechanical systems-based interdigital sensors were fabricated on oxidized single-crystal silicon surfaces by the maskless photolithography technique. The electrochemical impedance analysis of these sensors was done to detect liquefied petroleum gas (LPG) with and without coated particles of tin oxide (SnO2) in form of a thin layer. A thin film of SnO2 was spin-coated on the sensing surface of the interdigital sensor to induce selectivity to LPG that consists of a 60/40 mixture of propane and butane, respectively. This paper reports a novel strategy for gas detection under ambient temperature and humidity conditions. The response time of the coated sensor was encouraging and own a promising potential to the development of a complete efficient gas sensing system.

Tactile Sensing From Laser-Ablated Metallized PET Films

This paper reports the design, fabrication, and implementation of a novel sensor patch developed from commercial polyethylene terephthalate films metallized with aluminum on one side. The aluminum was ablated with laser to form interdigitated electrodes to make sensor prototypes. The interdigitated electrodes were patterned on the substrate with a laser cutter. Characterization of the prototypes was done to determine their operating frequency followed by experimentation. The prototypes have been used as a tactile sensor showing promising results for using these patches in applications with contact pressures considerably lesser than normal human contact pressure.

Wearable Electronics Sensors: Current Status and Future Opportunities

The technological advancement in the past three decades has impacted our lives and wellbeing significantly. Different aspects of monitoring our physiological parameters are considered. Wearable sensors are one of its most important areas that have an ongoing trend and have a huge tendency to rise in the future. The wearable sensors are the externally used devices attached to any individual to measure physiological parameters of interest. The range of wearable sensors varies from minuscule to large scaled devices physically fitted to the user operating on wired or wireless terms. Many common diseases affecting large number of people notably gait abnormalities, Parkinson’s disease are analysed by the wearable sensors. The use of wearable sensors has got a better prospect with improved technical qualities and a better understanding of the currently used research methodologies. This chapter deals with the overview of the current and past means of wearable sensors with its associated protocols used for communication. It concludes with the ways the currently dealt wearable sensors can be improved in future.

Flexible Printed Sensors for Ubiquitous Human Monitoring

The flexible printed sensors based on nanomaterials available currently have numerous challenges attached to it. The formation of nanocomposite for the electrodes is an issue mainly regarding the solubility of the conducting material. Mostly, the electrodes are not highly conductive in the flexible sensors fabricated due to the non-uniform distribution of conductive material in the polymer. The process of introducing conductive material as electrodes needs manual processing and thus becomes expensive. The sensitivity of the flexible sensor saturates with time due to the constant bending leading to deformation marks on the substrate material. This also leads to uneven surface and eventually inappropriate reading of the sensor. It is difficult to decrease the inter-electrode distance due to the spreading of the conductive ink in the printed sensors. There are many drawbacks to the current method of fabrication of flexible printed sensor. This research follows a novel approach to developing a sensor via the fabrication and characterization of a flexible, strain sensitive patch which would be used for bio-medical applications. Based on the laser-ablation technology, some prototype sensors have been designed and fabricated. It shows the experimental results obtained from the developed sensor on the detection of limb movements. The sensors would also be explored for other novel applications in future.

Urinary incontinence monitoring system using laser-induced graphene sensors

This paper presents the design and development of a sensor patch to be used in a sensing system to deal with the urinary incontinence problem primarily faced by women and elderly people. The sensor patches were developed from laser-induced graphene from low-cost commercial polyimide (PI) polymers. The graphene was manually transferred to a commercial tape, which was used as sensor patch for experimentation. Salt solutions with different concentrations were tested to determine the most sensitive frequency region of the sensor. The results are encouraging to further develop this sensor in a platform for a fully functional urinary incontinence detection system.

A Simple Embedded Sensor: Excitation and Interfacing

Some of the basic sensors and their operating principle have been explained in this chapter. There is the certain advantage of capacitive/inductive sensors over resistive sensors. The operating principle of capacitive sensors and type of measurement techniques are also explained. Finally, design and development of a low-cost portable sensing system were explained which can measure the impedance of a capacitive sensor and might be useful for different applications. There are some various applications explained by using capacitive sensors.