Piezo-resistive and thermo-resistance effects of highly-aligned CNT based macrostructures

Dau, Van Thanh; Tran, Canh‐Dung; Thanh, Tung Bui; Nguyen, Vy; Dinh, Thien Xuan

doi:10.1039/c6ra22872k

Cited by 21 publications

(13 citation statements)

References 67 publications

(63 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nowadays, among various sensors to detect human motion and monitor health condition, piezoresistive sensors (PRSs), which are typical sensors that transduce the external pressure into the resistance signal, have been widely used in wearable devices due to their advantages of cost‐efficient fabrication and simple structure . Normal PRSs with conductive polymers or particles are proved suitable sensing materials, but these materials are confronted with low sensitivity and poor stability especially in low‐pressure regimes. Different from the conventional PRSs, conductive porous sponges or foams have been developed, which are considered as alternative materials owing to their synergistic effect of high conductivity of active materials and excellent mechanical property of porous scaffold.…”

Section: Introductionmentioning

confidence: 99%

Highly Compressible Integrated Supercapacitor–Piezoresistance‐Sensor System with CNT–PDMS Sponge for Health Monitoring

Song

Chen

et al. 2017

Small

275

133

View full text Add to dashboard Cite

Rapid improvement of wearable electronics stimulates the demands for the matched functional devices and energy storage devices. Meanwhile, wearable microsystem requires every parts possessing high compressibility to accommodate large-scale mechanical deformations and complex conditions. In this work, a general carbon nanotube-polydimethylsiloxane (CNT-PDMS) sponge electrode is fabricated as the elementary component of the compressible system. CNT-PDMS sponge performs high sensitivity as a piezoresistance sensor, which is capable of detecting stress repeatedly and owns great electrochemical performance as a compressible supercapacitor which maintains stably under compressive strains, respectively. Assembled with the piezoresistance sensor and the compressible supercapacitor, such highly compressible integrated system can power and modulate the low-power electronic devices reliably. More importantly, attached to the epidermal skin or clothes, it can detect human motions, ranging from speech recognition to breathing record, thus showing feasibility in real-time health monitor and human-machine interfaces.

show abstract

Section: Introductionmentioning

confidence: 99%

Highly Compressible Integrated Supercapacitor–Piezoresistance‐Sensor System with CNT–PDMS Sponge for Health Monitoring

Song

Chen

et al. 2017

Small

275

133

View full text Add to dashboard Cite

show abstract

“…The resistance variations of hotwires were then converted to the velocity of ion wind by comparing the heat transfer coefficient of forced convection,

from generated ion winds with that of natural convection

from a still air [ 44 ], where

is the thermal conductivity, Ra is the Rayleigh number, d is the effective diameter of the hotwire, and

is the Reynolds number. The process was carried out using an subroutine C-code, which has been detailed in our recent publications [ 45 , 46 , 47 , 48 ]. The average velocities calculated from output voltage are plotted in Figure 7 b.…”

Section: Resultsmentioning

confidence: 99%

Transient Characteristics of a Fluidic Device for Circulatory Jet Flow

Phan

Dinh

Bui

et al. 2018

Sensors

View full text Add to dashboard Cite

In this paper, we report on the design, simulation, and experimental analysis of a miniaturized device that can generate multiple circulated jet flows. The device is actuated by a lead zirconate titanate (PZT) diaphragm. The flows in the device were studied using three-dimensional transient numerical simulation with the programmable open source OpenFOAM and was comparable to the experimental result. Each flow is verified by two hotwires mounted at two positions inside each consisting chamber. The experiment confirmed that the flow was successfully created, and it demonstrated good agreement with the simulation. In addition, a prospective application of the device as an angular rate sensor is also demonstrated. The device is robust, is minimal in size, and can contribute to the development of multi-axis fluidic inertial sensors, fluidic amplifiers, gas mixing, coupling, and analysis.

show abstract

“…The voltage of hotwires is used to determine the average velocity of flow at local areas around hotwire positions by comparing the heat transfer coefficient of forced convection(0.24 + 0.56 0.45 ⁄ ) with one by the natural convection (1.02 0.1 ) ⁄ of air with , Ra and d the thermal conductivity, Rayleigh number, effective diameter of the hotwire, respectively; and the Reynolds number of air flow. The calculation is carried out using our subroutine C-code whose details can be found in our recent publications [45], [46].…”

Section: Characterization Of Vortex Flow Using Hotwire Anemometrymentioning

confidence: 99%

Vortex flow generator utilizing synthetic jets by diaphragm vibration

Dau

Dinh

Bui

et al. 2018

International Journal of Mechanical Sciences

Self Cite

View full text Add to dashboard Cite

This paper develops a millimeter scale fully packaged device in which a vortex flow of high velocity is generated inside a chamber. Under the actuation by a lead zirconate titanate (PZT) diaphragm, a flow circulates with increasing velocity after each actuating circle to form a vortex in a cavity named as the vortex chamber. At each cycle, the vibration of the PZT diaphragm creates a small net air flow through a rectifying nozzle, generates a synthetic jet which propagates by a gradual circulation toward the vortex chamber and then backward the feedback chamber. The design of such device is firstly conducted by a numerical analysis whose results are considered as the base of our experimental setup. A vortex flow generated in a chamber of the device (named as the votex chamber) was observed by a high-speed camera. The present approach which was illustrated by both the simulation and experiment is potential in various applications related to the inertial sensing, fluidic amplifier and micro/nano particle trapping and mixing.

show abstract

Piezo-resistive and thermo-resistance effects of highly-aligned CNT based macrostructures

Abstract: Recent advances in assembling Carbon NanoTubes (CNTs) into macrostructures with outstanding properties, such as high tensile strength, high conductivity and porosity, and strong corrosive resistance, have underpinned potentially novel applications.

Cited by 21 publications

References 67 publications

Highly Compressible Integrated Supercapacitor–Piezoresistance‐Sensor System with CNT–PDMS Sponge for Health Monitoring

Highly Compressible Integrated Supercapacitor–Piezoresistance‐Sensor System with CNT–PDMS Sponge for Health Monitoring

Transient Characteristics of a Fluidic Device for Circulatory Jet Flow

Vortex flow generator utilizing synthetic jets by diaphragm vibration

Contact Info

Product

Resources

About