scholarly journals Polyurethane-Carbon Nanotubes Composite Dual Band Antenna for Wearable Applications

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2759
Author(s):  
Robert Olejník ◽  
Stanislav Goňa ◽  
Petr Slobodian ◽  
Jiří Matyáš ◽  
Robert Moučka ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Thermoplastic Polyurethane ◽  
Conductive Filler ◽  
Dip Coating ◽  
Dual Band ◽  
Wearable Electronics ◽  
Frequency Bands ◽  
Multi Wall Carbon Nanotubes ◽  
Dual Band Antenna ◽  
Base Composite

The design of a unipole and a dual band F-shaped antenna was conducted to find the best parameters of prepared antenna. Antenna radiator part is fully made of polymer and nonmetal base composite. Thermoplastic polyurethane (PU) was chosen as a matrix and multi-wall carbon nanotubes (MWCNT) as an electrical conductive filler, which creates conductive network. The use of the composite for the antenna has the advantage in simple preparation through dip coating technique. Minor disadvantage is the usage of solvent for composite preparation. Composite structure was used for radiator part of antenna. The antenna operates in 2.45 and 5.18 GHz frequency bands. DC conductivity of our PU/MWCNT composite is about 160 S/m. With this material, a unipole and a dual band F antenna were realized on 2 mm thick polypropylene substrate. Both antenna designs were also simulated using finite integration technique in the frequency domain (FI-FD). Measurements and full wave simulations of S11 of the antenna showed good agreement between measurements and simulations. Except for S11, the gain and radiation pattern of the antennas were measured and simulated. Maximum gain of the designed unipole antenna is around −10.0 and −5.5 dBi for 2.45 and 5.18 GHz frequency bands, respectively. The manufactured antennas are intended for application in wearable electronics, which can be used to monitor various activities such as walking, sleeping, heart rate or food consumption.

scholarly journals Microdome-Tunable Graphene/Carbon Nanotubes Pressure Sensors Based on Polystyrene Array for Wearable Electronics

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7385
Author(s):  
Xingjie Su ◽  
Chunli Luo ◽  
Weiguo Yan ◽  
Junyi Jiao ◽  
Dongzhou Zhong
Keyword(s):  
Carbon Nanotubes ◽  
Pressure Sensor ◽  
Self Assembly ◽  
Low Cost ◽  
Pressure Sensors ◽  
Conductive Filler ◽  
Human Motion ◽  
Wearable Electronics ◽  
Flexible Pressure Sensor ◽  
Human Finger

Resistive pressure sensors are appealing due to having several advantages, such as simple reading mechanisms, simple construction, and quick dynamic response. Achieving a constantly changeable microstructure of sensing materials is critical for the flexible pressure sensor and remains a difficulty. Herein, a flexible, tunable resistive pressure sensors is developed via simple, low-cost microsphere self-assembly and graphene/carbon nanotubes (CNTs) solution drop coating. The sensor uses polystyrene (PS) microspheres to construct an interlocked dome microstructure with graphene/CNTs as a conductive filler. The results indicate that the interlocked microdome-type pressure sensor has better sensitivity than the single microdome-type and single planar-type without surface microstructure. The pressure sensor’s sensitivity can be adjusted by varying the diameter of PS microspheres. In addition, the resistance of the sensor is also tunable by adjusting the number of graphene/CNT conductive coating layers. The developed flexible pressure sensor effectively detected human finger bending, demonstrating tremendous potential in human motion monitoring.

Design of Dual Band Antenna for WLAN Application

2014 ◽  
Vol 67 (3) ◽  
Author(s):  
M. Md. Shukor ◽  
M. Z. A. Abd. Aziz ◽  
B. H. Ahmad ◽  
M. K. Suaidi ◽  
M. A. Othman
Keyword(s):  
Frequency Response ◽  
Return Loss ◽  
Coplanar Waveguide ◽  
Dual Band ◽  
Ieee 802.11B ◽  
Resonant Frequencies ◽  
Ieee 802.11A ◽  
Frequency Bands ◽  
Dual Band Antenna

This paper presents the antenna designed with radiating structure of 3.5 for dual band applications. This antenna is designed and simulated by using CST Studio Suite software at 2.4 GHz and 5.2 GHz based on standard IEEE 802.11a (5.15 GHz-5.35 GHz) and IEEE 802.11b (2.4 GHz-2.48 GHz) frequency bands. The radiating structure 5 and 3 are designed to radiated at frequency 2.4 GHz and 5.2 GHz respectively. Then, both structures are combined to achieve dual band resonant frequencies. The techniques that have been used to achieve dual band resonant are by designing the 3.5 shaped by using planar and coplanar waveguide (CPW) structures. There are three designs of dual band antenna which are Design A, Design B and Design C. The optimum return loss for 2.4 GHz and 5.2 GHz frequency response are -16.44 dB and -18.78 dB respectively achieved by Design C. The changes on the position of radiating structure 3 will effects the frequency response, return loss and gain of the antenna.

scholarly journals Stretchable Strain Sensor for Human Motion Monitoring Based on an Intertwined-Coil Configuration

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1980
Author(s):  
Wei Pan ◽  
Wei Xia ◽  
Feng-Shuo Jiang ◽  
Xiao-Xiong Wang ◽  
Zhi-Guang Zhang ◽  
...  
Keyword(s):  
Thermoplastic Polyurethane ◽  
Strain Sensor ◽  
Dip Coating ◽  
Human Motion ◽  
Wearable Electronics ◽  
Special Configuration ◽  
Highly Stretchable ◽  
Application Potential ◽  
Promising Application ◽  
Human Motion Monitoring

Wearable electronics, such as sensors, actuators, and supercapacitors, have attracted broad interest owing to their promising applications. Nevertheless, practical problems involving their sensitivity and stretchability remain as challenges. In this work, efforts were devoted to fabricating a highly stretchable and sensitive strain sensor based on dip-coating of graphene onto an electrospun thermoplastic polyurethane (TPU) nanofibrous membrane, followed by spinning of the TPU/graphene nanomembrane into an intertwined-coil configuration. Owing to the intertwined-coil configuration and the synergy of the two structures (nanoscale fiber gap and microscale twisting of the fiber gap), the conductive strain sensor showed a stretchability of 1100%. The self-inter-locking of the sensor prevents the coils from uncoiling. Thanks to the intertwined-coil configuration, most of the fibers were wrapped into the coils in the configuration, thus avoiding the falling off of graphene. This special configuration also endowed our strain sensor with an ability of recovery under a strain of 400%, which is higher than the stretching limit of knees and elbows in human motion. The strain sensor detected not only subtle movements (such as perceiving a pulse and identifying spoken words), but also large movements (such as recognizing the motion of fingers, wrists, knees, etc.), showing promising application potential to perform as flexible strain sensors.

scholarly journals Array Design of 300 GHz Dual-Band Microstrip Antenna Based on Dual-Surfaced Multiple Split-Ring Resonators

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4912
Author(s):  
Shuhang Bie ◽  
Shi Pu
Keyword(s):  
Transmission Lines ◽  
Microstrip Antenna ◽  
Communication Systems ◽  
Ring Resonators ◽  
Dual Band ◽  
Split Ring ◽  
Coverage Area ◽  
Split Ring Resonators ◽  
Frequency Bands ◽  
Dual Band Antenna

To meet the increasing need of high-data-rate and broadband wireless communication systems, the devices and its circuits R&D under Millimeter, Sub-Millimeter, or even Terahertz (THz) frequency bands are attracting more and more attention from not only academic, but also industrial areas. Most of the former research on the THz waveband (0.1–10 THz) antenna design is mainly focused on realizing high directional gain, such as horn antennas, even though the coverage area is very limited when comparing with the current Wi-Fi system. One solution for the horizontally omnidirectional communication antenna is using the structure of multiple split-ring resonators (MSRRs). Aiming at this point, a novel 300 GHz microstrip antenna array based on the dual-surfaced multiple split-ring resonators (DSMSRRs) is proposed in this paper. By employing the two parallel microstrip transmission lines, different MSRRs are fed and connected on two surfaces of the PCB with a centrally symmetric way about them. The feeding port of the whole antenna is in between the centers of the two microstrip lines. Thus, this kind of structure is a so-called DSMSRR. Based on the different size of the MSRRs, different or multiple working wavebands can be achieved on the whole antenna. Firstly, in this paper, the quasi-static model is used to analyze the factors affecting the resonance frequency of MSRRs. Simulation and measured results demonstrate that the resonant frequency of the proposed array antenna is 300 GHz, which meets the design requirements of the expected frequency point and exhibits good radiation characteristics. Then, a dual-band antenna is designed on the above methods, and it is proved by simulation that the working frequency bands of the proposed dual-band antenna with reflection coefficient below −10 dB are 274.1–295.6 GHz and 306.3–313.4 GHz.

scholarly journals NOVEL COMPACT DUAL-BROADBAND PLANAR METAMATERIAL ANTENNA

2017 ◽  
Vol 55 (3) ◽  
pp. 334
Author(s):  
Dang Nhu Dinh ◽  
Huynh Nguyen Bao Phuong ◽  
Dinh Thanh Liem ◽  
Hoang Phuong Chi ◽  
Dao Ngoc Chien
Keyword(s):  
Transmission Line ◽  
Resonance Frequency ◽  
Coplanar Waveguide ◽  
Dual Band ◽  
Frequency Bands ◽  
Left Handed ◽  
Dual Band Antenna ◽  
Metamaterial Antenna ◽  
Measurement Results

This paper proposes a novel uni-planar dual-band antenna using Composite Right Left Handed (CRLH) transmission line (CRLH-TL). Proposed antenna is designed based on the fringing effects of metamaterials and combined with coplanar waveguide (CPW) feeding in order to create two frequency bands for WLAN applications at the 2.4 and 5.5 GHz bands. Principle of gradual transform is applied to the antenna for extending the resonance frequency ranges. Optimized metamaterial antenna are fabricated and measured. Measurement results showed that the antenna operates in two broad frequency ranges spreading from 1.8 to 3.62 GHz and from 4.85 to 7.52 GHz with very compact overall dimensions of 18 mm × 16 mm (0,147 λ0 × 0.13λ0).

Design of a Compact Bluetooth and UWB Antenna for Wireless Communications

2014 ◽  
Vol 711 ◽  
pp. 312-315
Author(s):  
Hui Feng ◽  
Hong Bao Mao ◽  
Guang Zheng Long
Keyword(s):  
Wireless Communications ◽  
Surface Area ◽  
Microstrip Line ◽  
Ultra Wideband ◽  
Antenna Design ◽  
Dual Band ◽  
Uwb Antenna ◽  
Frequency Bands ◽  
Dual Band Antenna

A compact and planar dual band antenna for Bluetooth and ultra-wideband (UWB) is presented. The antenna exhibits a dual band operation covering Bluetooth (2.4-2.484 GHz) and UWB (3.1-10.6 GHz) frequency bands. It is composed of a semi-circular and an L-shaped strip and fed by a microstrip line and built on a FR4 substrate with only 23 × 35 mm2surface area. Details of the antenna design and measured results are presented and discussed.

scholarly journals A Compact SRR Loaded Dual Band Antenna with Modified Ground for Terahertz Applications

2019 ◽  
Vol 8 (4) ◽  
pp. 11422-11424
Keyword(s):  
Resonant Frequency ◽  
Return Loss ◽  
Dual Band ◽  
Frequency Bands ◽  
Triple Frequency ◽  
Dual Band Antenna ◽  
Compact Size ◽  
Terahertz Applications ◽  
Triple Band

A compact triple band MS antenna for Terahertz Applications is designed. The proposed MS antenna exhibit triple frequency bands by loading SRR with Rogers RT-6006 substrate. The designed antenna resonates at triple frequencies. The first resonant frequency is shown at 600 GHz (in between the band 650 GHz - 670 GHz) with maximum return loss of - 34.485 dB. The second resonant frequency is shown at 699 GHz (in between the band 680 GHz -710 GHz) with maximum return loss of -28 dB and third resonant frequency is shown at 757GHz (in between the band 750 GHz -775GHz) . The give MS antenna with a compact size of = 600 µm x 400 µm is simulated. The designed antenna exhibit as per required standards for Terahertz Applications.

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