Motion Detection Sensors Research Articles

Printed Directional Bending Sensor with High Sensitivity and Low Hysteresis for Human Motion Detection and Soft Robotic Perception.

We present a high-performance flexible bending strain sensor for directional motion detection of human hands and soft robotic grippers. The sensor was fabricated using a printable porous conductive composite composed of polydimethylsiloxane (PDMS) and carbon black (CB). The utilization of a deep eutectic solvent (DES) in the ink formulation induced a phase segregation between the CB and PDMS and led to a porous structure inside the printed films after being vapored. This simple and spontaneously formed conductive architecture provided superior directional bend-sensing characteristics compared to conventional random composites. The resulting flexible bending sensors displayed high bidirectional sensitivity (gauge factor of 45.6 under compressive bending and 35.2 under tensile bending), negligible hysteresis, good linearity (>0.99), and excellent bending durability (over 10,000 cycles). The multifunctional applications of these sensors, including human motion detection, object-shape monitoring, and robotic perceptions, are demonstrated as a proof-of-concept.

Functionally integrated conductive organohydrogel sensor for wearable motion detection, triboelectric nanogenerator and non-contact sensing

In the field of wearable devices, hydrogel has become a new material due to its excellent flexibility and adjustable multifunctionality. However, there are still many problems in practical application, which cannot meet the requirements of people for flexible electronic devices. Herein, a stretchable, self-adhesive, anti-freezing and moisturizing ion-conductive organohydrogel was successfully prepared. This organohydrogel can exhibit adjustable optical properties in different solvents, and the strain sensor based on it can exhibits excellent sensing capability and real-time responsiveness to various strains, pressures and human body. In addition, the organohydrogel exhibits excellent energy harvesting capabilities when it was assembled with Ecoflex elastomers to form a triboelectric nanogenerator (TENG). And when it was assembled with Ecoflex elastomer to form a non-contact capacitive sensor, it can achieve good proximity sensing stability. Therefore, it can be seen that the multifunctional organohydrogel provides an idea for the design and preparation of advanced versatile flexible sensors.

Ionic Gel Based Multifunctional Sensor for Body Temperature Monitoring and Joint Motion Detection

Flexible temperature and strain sensors are key components of wearable devices for healthcare monitoring. Currently, the insufficient precision, undesirable mechanical properties, and the cross interference between different external stimuli are still bottleneck problems for flexible sensors especially in body temperature and human motion monitoring. Herein, an ionic gel based on ionic liquids (ILs) and commercial thermoplastic polyurethane (TPU) fiber is fabricated via a feasible and scalable immersion method for temperature and strain multifunctional sensing. Wearable sensor based on ionic gel exhibits high temperature sensitivity (2.73% ◦C−1) and sufficient resolution (0.1 ◦C) in the skin temperature range. Meanwhile, the sensor exhibits linear and stable strain sensing performance and has the ability to respond to tiny strains. More importantly, the multifunctional fiber‐like sensor is easy to integrate with traditional textile, which is beneficial to solve the wearability problems such as discomfort and impermeability in practical applications. Notably, the stimulus caused by strain can be almost avoided by sewing smart fibers into S‐shape during the temperature monitoring, which helps decouple the temperature and strain signals. As prepared intelligent textiles can accurately capture small fluctuations in temperature and detect the action amplitude of the human body, which is important for disease prediction and rehabilitation training of patients.

SISTEM KEAMANAN RUANGAN MENGGUNAKAN SENSOR PIR DENGAN BUZZER ALARM DAN EMAIL NOTIFIKASI PADA SMAN 15 KOTA BEKASI

Security systems using motion sensors provide the benefit of knowing crimes that occur using the prototype method, PIR sensors (Passive Infrared Receiver) as sensors to detect human motion so that, when human movement is detected by the PIR sensor, it will sound an alarm and send message notifications via e-mail users use e-mail, so users can find out about actions quickly. The research was carried out by installing motion detection sensors with buzzer alarms and email notifications in the principal, teacher, and administration rooms.

Tendon-Inspired Anisotropic Hydrogels with Excellent Mechanical Properties for Strain Sensors.

Anisotropic conductive hydrogels mimicking the natural tissues with high mechanical properties and intelligent sensing have played an important role in the field of flexible electronic devices. Herein, tensile remodeling, drying, and subsequent ion cross-linking methods were used to construct anisotropic hydrogels, which were inspired by the orientation and functionality of tendons. Due to the anisotropic arrangement of the polymer network, the mechanical performance and electrical conductivity were greatly improved in specific directions. The tensile stress and elastic modulus of the hydrogel along the network orientation were 29.82 and 28.53 MPa, which were higher than those along the vertical orientation, 9.63 and 11.7 MPa, respectively. Moreover, the hydrogels exhibited structure-dependent anisotropic sensing. The gauge factors (GFs) parallel to the prestretching direction were greater than the GF along the vertical direction. Thus, the tendon-inspired conductive hydrogels with anisotropy could be used as flexible sensors for joint motion detection and voice recognition. The anisotropic hydrogel-based sensors are highly expected to promote the great development of emerging soft electronics and medical detection.

Totally dynamically cross-linked dual-network conductive hydrogel with superb and rapid self-healing ability for motion detection sensors

To overcome the status quo of fragile network and single function in the single-network hydrogel, this work designed and fabricated a dual-network O-CMCS (O-carboxymethyl chitosan)/PVA (polyvinyl alcohol) PBOC conductive hydrogel based on two kinds of totally dynamic reversible cross-linking networks. The PBOC conductive hydrogel combined a flexible O-PT (oxidized pectin)/O-CMCS network with a rigid PVA-borax network, and CNTs (carbon nanotubes) were introduced to improve its toughness and conductivity. Its structural characteristics were investigated through Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), X-ray diffractometer (XRD), nuclear magnetic resonance (NMR) and other techniques. Its superb and rapid self-healing property was confirmed through dynamic rheological tests, and its electrical property was studied through an electrochemical workstation. The co-existence of the dual networks endowed the PBOC conductive hydrogel with excellent stretchable property (821% of the maximum elongation at break), and it could quickly self-heal within 60 s after being cut due to the intense interaction of totally reversible multiple dynamic bonding. Notably, the PBOC conductive hydrogel strain sensor exhibited high strain sensitivity with GF (gauge factor) of 8.44 at 800% strain and could accurately detect all kinds of human motions (e.g. finger bending, wrist bending and elbow bending, etc.), confirming its tremendous application potential in the field of wearable sensor devices.

Self-adhesive, ionic-conductive, mechanically robust cellulose-based organogels with anti-freezing and rapid recovery properties for flexible sensors

Cellulose-based functional gels have received considerable attention because of their good mechanical properties, biocompatibility, and low cost. However, the preparation of cellulose gels with self-adhesion, mechanical robustness, ionic conductivity, anti-freezing ability, and environmental stability remains a challenge. Here, gallic acid esterified microcrystalline cellulose (MCC-GA) was obtained by grafting gallic acid (GA) onto the macromolecular chains of microcrystalline cellulose (MCC) through a one-step esterification method. Then the prepared MCC-GA was dissolved in Lithium chloride/dimethyl sulfoxide (LiCl/DMSO) system and polymerized with acrylic acid (AA) to prepare a multi-functional cellulose-based organogel. The prepared MCC-GA/polyacrylic acid (PAA) organogels exhibited enhanced interfacial adhesion through hydrogen bonding, π–π interactions, and electrostatic interactions. Additionally, the MCC–GA/PAA organogels could withstand 95 % of the compressive deformation and rapidly self-recover owing to chemical cross-linking and dynamic non-covalent interactions. The organogels also exhibited excellent anti-freezing properties (up to −80 °C), solvent retention, and ionic conductivity. Considering its excellent overall performance, the MCC–GA/PAA organogel was used as an effective flexible sensor for human motion detection and is expected to play an important role in the future development of flexible bioelectronics.

Facile and Economical Fabrication of Superhydrophobic Flexible Resistive Strain Sensors for Human Motion Detection

Superhydrophobic flexible strain sensors have great application value in the fields of personal health monitoring, human motion detection, and soft robotics due to their good flexibility and high sensitivity. However, complicated preparation processes and costly processing procedures have limited their development. To overcome these limitations, in this work we develop a facile and low-cost method for fabricating superhydrophobic flexible strain sensor via spraying carbon black (CB) nanoparticles dispersed in a thermoplastic elastomer (SEBS) solution on a polydimethylsiloxane (PDMS) flexible substrate. The prepared strain sensor had a large water contact angle of 153 ± 2.83° and a small rolling angle of 8.5 ± 1.04°, and exhibited excellent self-cleaning property. Due to the excellent superhydrophobicity, aqueous acid, salt, and alkali could quickly roll off the flexible strain sensor. In addition, the sensor showed excellent sensitivity (gauge factor (GF) of 5.4–7.35), wide sensing ranges (stretching: over 70%), good linearity (three linear regions), low hysteresis (hysteresis error of 4.8%), and a stable response over 100 stretching-releasing cycles. Moreover, the sensor was also capable of effectively detecting human motion signals like finger bending and wrist bending, showing promising application prospects in wearable electronic devices, personalized health monitoring, etc.

Self-adhesive, self-healing, biocompatible and conductive polyacrylamide nanocomposite hydrogels for reliable strain and pressure sensors

To realize long-term and stable applications of wearable and flexible sensors for motion detection, health analysis and wisdom medication in harsh environments, self-healing, self-adhesive, electrically conductive and biocompatible polyacrylamide (PAM) nanocomposite hydrogels are fabricated as flexible strain or pressure sensors by in situ polymerization of acrylamide in the presence of polydopamine-modified carbon nanotubes (PDA@CNTs) for effectively detecting human motions, identifying materials and their shapes, and transmitting health information. The resultant PDA@CNT/PAM nanocomposite hydrogel exhibits a high self-healing efficiency of 97.3%, excellent biocompatibility, and strong adhesion with substrates based on hydrogen bonding and π–π stacking interactions. Based on the piezoresistive effect, the nanocomposite hydrogel-based strain sensor exhibits a high sense gauge factor of 3.93 at a strain of 400% and responds quickly with a fast response time of 76 ms when detecting human movement. Thanks to the contact electrification and the electrostatic induction, the nanocomposite hydrogel-based pressure sensor can respond to pressure linearly and generate voltage signals in the absence of an additional power supply. Furthermore, the self-powered smart ring made of the silicone rubber-coated PDA@CNT/PAM hydrogel enables efficient and concise information transmission via Morse code.

Multifunctional hydrophobic fabric-based strain sensor for human motion detection and personal thermal management

• Sensors with multifunctional biomedical applications are rational designed and fabricated. • The developed PDMS treatment enhances sensor's durability and stability. • The smart fabric has excellent photothermal and Joule-thermal performance as thermal management device. • Benefit from good anti-wetting and photothermal property, smart fabric exhibits superior de-icing ability. Multifunctional flexible devices for human motion detection and thermal management raised great attention as the problem of the aging population is becoming more and more serious. However, it is still a challenge to endow the devices with excellent stability and wide application scope. Here we prepared a hydrophobic and conductive fabric-based strain sensor for smart fabric via successively coating with polydopamine (PDA), polyaniline (PANI), polypyrrole (PPy), and polydimethylsiloxane (PDMS) through in-situ polymerization and dip-coating, which could be used for strain sensor and wearable heater both in air and underwater. The obtained sample exhibited a fast electrical response in 500 ms and could withstand 10000 times stretching-releasing cycles, additionally, the sample exhibited satisfactory electro-thermal and photo-thermal performances. As a whole, the multifunctional fabric-based devices with excellent performances show great potential to be applied in medical monitoring and personal care, especially for aged and disabled persons.

Durable, breathable, sweat-resistant, and degradable flexible sensors for human motion detection

Paper-based wearable sensors are becoming popular in flexible electronic devices, owing to their good degradability, high permeability, low cost, and scalable production. However, the strong water absorption of the paper limits its application in wearable strain sensors. Herein, a hydrophobic and breathable paper/MXene/sizing agent (PMS) flexible strain sensor is reported by facile successive dip coating methods. The MXene layer endows the composite with high sensing performance while the sizing agent layer ensures its hydrophobicity. This PMS sensing film demonstrated high sensitivity (gauge factor, GF = 161) in the bending angle of 0-120° and excellent durability of 100,000 cycles in bending deformation of 30°. Benefiting from the paper substrate and the biomass sizing agent, this sensor exhibits superior hydrophobicity (contact angle, CA = 133.4°), good air permeability (154.08 mm/s), and high degradability. For the proof of concept, human movement detection and wearable Morse code wireless transmission systems under water conditions are demonstrated. This work presents an appropriate strategy for building comfortable and versatile paper-based wearable electronics.

An IoT-based Smart Home Application with Barrier-Free Stairs for Disabled/Elderly People

Home automation based on the Internet of Things (IoT) includes various components such as lighting, security, and remote control. Smart Home (SH) components should be varied and customised according to the user's specific needs. Therefore, in this study, a SH system needed by users with specials is designed and implemented on a model. The NodeMCU microcontroller with ESP8266 Wi-Fi module, Radio Frequency Identification (RFID) tags, temperature-humidity, motion detection, gas and moisture sensors and several actuators are used to build the system. Thanks to If This Then That (IFTTT), Google Assistant, and Blynk, the SH components can be managed remotely and with voice commands via a user-friendly Android-based mobile interface. The multiple control system and the ability to control the home components with different methods make this study comprehensive. In particular, the barrier-free stairs design has added innovation to the SH system for disabled people. Thus, the accessibility, security, and comfort requirements of disabled people are met, and their quality of life is improved to live independently.

3D Printable Self-Adhesive and Self-Healing Ionotronic Hydrogels for Wearable Healthcare Devices.

Ionotronic hydrogels have attracted significant attention in emerging fields such as wearable devices, flexible electronics, and energy devices. To date, the design of multifunctional ionotronic hydrogels with strong interfacial adhesion, rapid self-healing, three-dimensional (3D) printing processability, and high conductivity are key requirements for future wearable devices. Herein, we report the rational design and facile synthesis of 3D printable, self-adhesive, self-healing, and conductive ionotronic hydrogels based on the synergistic dual reversible interactions of poly(vinyl alcohol), borax, pectin, and tannic acid. Multifunctional ionotronic hydrogels exhibit strong adhesion to various substrates with different roughness and chemical components, including porcine skin, glass, nitrile gloves, and plastics (normal adhesion strength of 55 kPa on the skin). In addition, the ionotronic hydrogels exhibit intrinsic ionic conductivity imparting strain-sensing properties with a gauge factor of 2.5 up to a wide detection range of approximately 2000%, as well as improved self-healing behavior. Based on these multifunctional properties, we further demonstrate the use of ionotronic hydrogels in the 3D printing process for implementing complex patterns as wearable strain sensors for human motion detection. This study is expected to provide a new avenue for the design of multifunctional ionotronic hydrogels, enabling their potential applications in wearable healthcare devices.

DESIGN AND IMPLEMENTATION OF A SMART HOME AUTOMATION SYSTEM

Objective: Due to the rapid development of various technologies and communication devices, the use of the Internet of Things (IoT) for automation has become increasingly common in non-industrial environments. It has integrated well into our day-to-day activities, leading us toward the use of smart home technology. Smart home systems are intelligent system that provide control to home appliances and also security systems. There are limited numbers of intelligent systems that address multiple aspects of the home automation, such as appliances control, security bridge detection, and reducing energy consumption and cost simultaneously. Hence, this research developed a system that solves these problems with an intelligent home automation system. Methods: The designed system was based on Arduino ATMEGA328P microcontroller, MQ2 sensor for gas detection, passive infrared (IR) sensor for motion detection, and flame sensor to detect fire outbreak. Arduino ATMEGA328P was used as a central controlling unit that controls the flow of system operations to achieved smart home automation system. Results: The system sends audible alarms through a buzzer to draw the user’s immediate attention. It also sends a warning message to the user’s mobile phone through the global system for mobile communication module. Conclusion: The system achieved a precision rate of 94.44% and provided a cost-effective platform for interconnecting a variety of devices and various sensors in a home through the IoT.

Multiple Tendon-inspired Sensors for Hand Motion Detection

Realistic presentation by a virtual avatar and detection are critical in a motion tracking system. Specifically, because the hand is an essential body part that interacts with other objects or humans in a virtual environment, accurate behavior tracking in real time is required. In this study, we propose a hand motion detection glove using multiple tendon-inspired sensors. Remarkably, there are no sensors or electronics in the hand part of the glove. Piezoelectric sensors are positioned on the wrist part of the glove, which are connected to the tendon in the glove. The elongated piezoelectric sensors detect the angle from joint changes caused by motions of the hand. In addition, we design a case for installing multiple sensors on many joints of the fingers. To demonstrate the sensing ability of the bending motion of the finger, a series of sensor tests is conducted using a finger structure setup. We obtain sensing results with changes in the rotational angles and frequencies. Moreover, the rotational angle can be estimated from the sensing data. Based on these results, a virtual hand system following real hand motion is constructed utilizing a motion detection glove with multiple tendon-inspired sensors. Finally, we investigate the effects of Young’s modulus, number of threads, and the structure of the elastic thread to enhance the output of the sensors.

IoT-Based Cotton Plant Pest Detection and Smart-Response System

IoT technology and drones are indeed a step towards modernization. Everything from field monitoring to pest identification is being conducted through these technologies. In this paper, we consider the issue of smart pest detection and management of cotton plants which is an important crop for an agricultural country. We proposed an IoT framework to detect insects through motion detection sensors and then receive an automatic response using drones based targeted spray. In our proposed method, we also explored the use of drones to improve field surveillance and then proposed a predictive algorithm for a pest detection response system using a decision-making theory. To validate the working behavior of our framework, we have included the simulation results of the tested scenarios in the cup-carbon IoT simulator. The purpose of our work is to modernize pest management so that farmers can not only attain higher profits but can also increase the quantity and quality of their crops.

Обробка сигналів у фасетних системах технічного зору

The article presents an overview of bio-similar motion sensors facet systems of technical vision – the Reichard correlation detector, the Horridge and Nguyen model, and it proposed the universal motion detection sensor. This sensor contains a microcontroller that quickly calculates the correlation function and its maximum value to find the direction and speed of movement in the field of view. The principles of their operation, advantages, disadvantages, and possibilities of application are considered.

Highly stretchable strain sensors based on gold thin film reinforced with carbon nanofibers

Flexible piezoresistive sensors are often fabricated by depositing a conductive layer such as platinum, gold, graphene thin films, or conductive nanoparticles onto an elastic substrate. However, due to the intrinsic brittleness of the conductive materials, this method usually results in sensors with limited stretchability. Herein, we demonstrate a new technique to greatly increase the stretchability of piezoresistive strain sensors based on gold (Au) thin films by being hybridized with carbon nanofibers (CNFs). Sensors based on Au thin film fail electrically at a very small strain (∼ 4.5%). In contrast, the sensors based on hybridized Au-CNFs thin film show a significantly increased failure strain up to ∼ 225%. Introducing one-dimensional CNFs enables a greatly enlarged workable strain range by bridging and deflecting the microcracks formed in the Au thin film during stretching. This can effectively prevent the formation of lengthy, channel-like straight cracks that cause electrical failure under low strains. The high-performance sensors have shown great potential for use as wearable sensors for motion detection, such as detecting joint bending. Moreover, the potential of the sensors in detecting airflow similar to human respiratory airflow level has been demonstrated.

Preparation of Salt-Induced Ultra-Stretchable Nanocellulose Composite Hydrogel for Self-Powered Sensors.

Hydrogels have attracted much attraction for promising flexible electronics due to the versatile tunability of the properties. However, there is still a big obstacle to balance between the multi-properties and performance of wearable electronics. Herein, we propose a salt-percolated nanocellulose composite hydrogel which was fabricated via radical polymerization with acrylic acid as polymer networks (NaCl-CNCs-PAA). CNCs were utilized as a reinforcing agent to enhance the mechanical properties of the hydrogel. Moreover, the abundant hydroxyl groups endow the hydrogel with noncovalent interactions, such as hydrogen bonding, and the robustness of the hydrogel was thus improved. NaCl incorporation induced the electrostatic interaction between CNCs and PAA polymer blocks, thus facilitating the improvement of the stretchability of the hydrogel. The as-obtained hydrogel exhibited excellent stretchability, ionic conductivity, mechanical robustness and anti-freezing properties, making it suitable for self-powered sensing applications. A single-mode triboelectric nanogenerator (C-TENG) was fabricated by utilizing the composite hydrogel as electrodes. This C-TENG could effectively convert biomechanical energy to electricity (89.2 V, 1.8 µA, 32.1 nC, and the max power density of 60.8 mW m-2 at 1.5 Hz.) Moreover, the composite hydrogel was applied for strain sensing to detect human motions. The nanocellulose composite hydrogel can achieve the application as a power supply in integrated sensing systems and as a strain sensor for human motion detection.

A self-powered wearable seizure-monitoring/brain-stimulating system for potential epilepsy treatment

A new self-powered wearable body-detecting/brain-stimulating system for monitoring and restraining epilepsy has been fabricated. The system can monitor body motion in real time and transmit the stimulus signals to brain for restraining the epileptic seizures. The system is composed of energy harvesting module, the body motion detection sensor, the data processing center, and neural stimulator. An arch-shaped device made of piezoelectric ceramic transducer (lead zirconate titanate; PZT) as energy harvesting module can convert the mechanical energy generated by body movement into electricity power. The motion detection sensor is made of polyvinylidene fluoride (PVDF) doped with zinc oxide (ZnO) nanostructures, which can detect the tiny movements of the human body and transmit sensing signals to the data processing center. The data processing center can determine the epileptic seizure and generate neural stimulating signals. By stimulating the dentate gyrus/hilus brain region of mice, the total duration of epileptic seizures in mice is significantly reduced by 40–50%. This new self-powered strategy demonstrates the potential of brain-machine-interface system for personalized treatment of brain disease.