Abstract null null New target applications for microfluidic devices have been focused on home usability, wearability and cost-effectiveness. Towards these goals, in this work, a controllable, bendable, and all‑organic, nozzle‑diffuser microfluidic pump was designed, fabricated and tested. First, to resolve the crucial issue of high driving voltage, the ferroelectric polymer poly(vinylidene fluoride‑trifluoroethylene) (P(VDF‑TrFE)) was optimized by adding core‑shell structured Al2O3@CNT nanofillers. The membrane so developed with 1.1 wt% Al2O3@CNT showed an increase by nearly 7 times in the induced strain in comparison to the neat P(VDF‑TrFE) at low electric fields, because the modified membrane simultaneously achieved a lower coercive electric field and a higher polarization. Accordingly, the required operating voltage of the microfluidic pump integrated with optimized membrane significantly decreased from 1000 V to 160 V. Meanwhile, this pump exhibited a wider range of flow rates (13–135 µL/min) than the reported results, associated with the higher output pressure in our membranes. Importantly, the designed pump still possessed an excellent controllability of the fluidic processes, though it underwent a large bending up to 74°. Consequently, the extremely promising application of the as‑prepared microfluidic pump in wearable, biomedical devices was demonstrated.
Last. Zuo-Guang Ye(SFU: Simon Fraser University)H-Index: 61
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Although the ultra-large induced strain of ferroelectric polymers has been achieved under an electric field near breakdown strength, the high driving voltage has been a long-standing obstacle for their safety applications in the actuator, transducer, wearable devices. To resolve this issue, novel core–shell structured CNT–Al2O3 nanoparticles grown via atomic layer deposition are utilized to improve the electromechanical properties of P(VDF-TrFE)-based nanocomposites under low applied fields. The...
#1Pingan Zhu(HKU: University of Hong Kong)H-Index: 13
#2Rifei Chen(HKU: University of Hong Kong)H-Index: 1
Last. Liqiu Wang(HKU: University of Hong Kong)H-Index: 41
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Soft actuators have the potential of revolutionizing the field of robotics. However, it has been a long-standing challenge to achieve simultaneously: i) miniaturization of soft actuators, ii) high contrast between materials properties at their "on" and "off" states, iii) significant actuation for high-payload mechanical work, and iv) ability to perform diverse shape transformations. This challenge is addressed by synergistically utilizing structural concepts found in the dermis of sea cucumbers ...
#1Kiersten D. Lenz(LANL: Los Alamos National Laboratory)H-Index: 1
#2Shailja Jakhar(LANL: Los Alamos National Laboratory)H-Index: 2
Last. Harshini Mukundan(LANL: Los Alamos National Laboratory)H-Index: 16
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The separation of biomarkers from blood is straightforward in most molecular biology laboratories. However, separation in resource-limited settings, allowing for the successful removal of biomarkers for diagnostic applications, is not always possible. The situation is further complicated by the need to separate hydrophobic signatures such as lipids from blood. Herein, we present a microfluidic device capable of centrifugal separation of serum from blood at the point of need with a system that is...
#1Yang Liu(PSU: Pennsylvania State University)H-Index: 28
#2Tiannan Yang(PSU: Pennsylvania State University)H-Index: 21
Last. Qing Wang(PSU: Pennsylvania State University)H-Index: 76
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Both experimental results and theoretical models suggest the decisive role of the filler-matrix interfaces on the dielectric, piezoelectric, pyroelectric, and electrocaloric properties of ferroelectric polymer nanocomposites. However, there remains a lack of direct structural evidence to support the so-called interfacial effect in dielectric nanocomposites. Here, a chemical mapping of the interfacial coupling between the nanofiller and the polymer matrix in ferroelectric polymer nanocomposites b...
Last. Zuo-Guang Ye(SFU: Simon Fraser University)H-Index: 61
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Abstract Reducing the operating voltage of dielectric elastomer actuator (DEA) without compromising breakdown strength (Eb) and elasticity has been one of the grand challenges to its practical application in various fields, such as the wearble devices. In this study, novel dielectric elastomers offering intrinsically good integrated performances are achieved by introducing CNT-Al2O3 core-shell nanostructures to form various nanocomposites. Dielectric constants (er) of these nanocomposites show a...
Last. K.M. Liew(CityU: City University of Hong Kong)H-Index: 110
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Abstract Although carbon nanotube (CNT) is an excellent additive in geopolymer, the effect of its chemical bonding at interfaces is not well understood. This paper explores the effects of interfacial bonding on the structure, dynamics and mechanical properties of CNT-geopolymer nanocomposites via molecular dynamics simulations. Our findings from the structural analysis reveal that the interfacial bonding decreases the thickness of the “interfacial van der waals (vdW) excluded volume” and interph...
In this study, a novel rotating permanent magnetic actuator (PMA) system is proposed to manipulate magnetic nanofluids to pump of chemicals inside micro-sized channels with a circular path. The PMA consists of two permanent magnet pairs and a rotor-like structure. A semicircular-shaped microchannel with a square cross-section area is located at the top of the actuator in order to investigate the performance of the PMA. Fe3O4-water magnetic nanofluid is employed as a working fluid for the manipul...
Last. Zhicheng Zhang(Xi'an Jiaotong University)H-Index: 30
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Poly(vinylidene fluoride) (PVDF)-based relaxor ferroelectric polymers, synthesized from the physical or chemical modification of β-PVDF and P(VDF–TrFE) (TrFE refers trifluoroethylene), show high thickness strain under an external field, which allows them to be employed as electroactive materials for actuation, sensor, and artificial muscle applications. In an effort to disclose the formation mechanism of electrostrain, a series of P(VDF–TrFE–CTFE) (CTFE is chlorotrifluoroethylene) copolymers are...
#1Chao Liu(CAS: Chinese Academy of Sciences)H-Index: 64
#2Qiang Feng(CAS: Chinese Academy of Sciences)H-Index: 22
Last. Jiashu Sun(CAS: Chinese Academy of Sciences)H-Index: 40
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: Lipid nanovesicles, including endogenous exosomes and synthetic lipid nanoparticles, have shown great potential in disease diagnostics, drug delivery, and cancer biology. Naturally secreted nanovesicles are promising biomarkers for early detection of cancers in vitro. Synthetic nanovesicles serve as robust drug delivery systems with enhanced tumor targeting in vivo. Microfluidic platforms with features of excellent flow control and rapid mixing are exploited as versatile tools for studying lip...
