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Lyanne Valdez, Henry Shum, Isamar Ortiz-Rivera, Anna C Balazs, Ayusman Sen
Immobilized enzymes generate net fluid flow when exposed to specific reagents in solution. Thus, they function as self-powered platforms that combine sensing and on-demand fluid pumping. To uncover the mechanism of pumping, we examine the effects of solutal and thermal buoyancy on the behavior of phosphatase-based micropumps, using a series of reactants with known thermodynamic and kinetic parameters. By combining modeling and experiments, we perform the first quantitative comparison of thermal and solutal effects in an enzyme micropump system...
March 27, 2017: Soft Matter
Erh-Chia Yeh, Chi-Cheng Fu, Lucy Hu, Rohan Thakur, Jeffrey Feng, Luke P Lee
Portable, low-cost, and quantitative nucleic acid detection is desirable for point-of-care diagnostics; however, current polymerase chain reaction testing often requires time-consuming multiple steps and costly equipment. We report an integrated microfluidic diagnostic device capable of on-site quantitative nucleic acid detection directly from the blood without separate sample preparation steps. First, we prepatterned the amplification initiator [magnesium acetate (MgOAc)] on the chip to enable digital nucleic acid amplification...
March 2017: Science Advances
Xiaoxue Song, Fei Hui, Keith Gilmore, Bingru Wang, Guangyin Jing, Zhongchao Fan, Enric Grustan-Gutierrez, Yuanyuan Shi, Lucia Lombardi, Stephen A Hodge, Andrea C Ferrari, Mario Lanza
The development of piezoelectric layered materials may be one of the key elements enabling expansion of nanotechnology, as they offer a solution for the construction of efficient transducers for a wide range of applications, including self-powered devices. Here, we investigate the piezoelectric effect in multilayer (ML) stepped MoS2 flakes obtained by liquid-phase exfoliation, which is especially interesting because it may allow the scalable fabrication of electronic devices using large area deposition techniques (e...
March 24, 2017: Nanoscale
Chuan Li, Wenbo Luo, Xingzhao Liu, Dong Xu, Kai He
The 0.7Pb(Mg1/3Nb2/3)O₃-0.3PbTiO₃(0.7PMN-0.3PT) nanorods were obtained via hydrothermal method with high yield (over 78%). Then, new piezoelectric nanocomposites based on (1-x)Pb(Mg1/3Nb2/3)O₃-xPbTiO₃ (PMN-PT) nanorods were fabricated by dispersing the 0.7PMN-0.3PT nanorods into piezoelectric poly(vinylidene fluoride) (PVDF) polymer. The mechanical behaviors of the nanocomposites were investigated. The voltage and current generation of PMN-PT/PVDF nanocomposites were also measured. The results showed that the tensile strength, yield strength, and Young's modulus of nanocomposites were enhanced as compared to that of the pure PVDF...
April 11, 2016: Nanomaterials
Tao Li, Jingdian Zou, Fei Xing, Meng Zhang, Xia Cao, Ning Wang, Zhong Lin Wang
Triboelectric nanogenerators (TENGs) can be applied for the next generation of artificial intelligent products, where skin-like tactile sensing advances the ability of robotics to feel and interpret environment. In this paper, a flexible and thin tactile sensor was developed on the basis of dual-mode TENGs. The effective transduction of touch and pressure stimulus into independent and interpretable electrical signals permits the instantaneous sensing of location and pressure with a plane resolution of 2 mm, a high-pressure-sensing sensitivity up to 28 mV·N(-1), and a linear pressure detection ranging from 40 to 140 N...
March 23, 2017: ACS Nano
Buddha Deka Boruah, Shanmukh Naidu Majji, Abha Misra
The unique photo-charge characteristics of chlorine-doped zinc oxide nanorods (Cl-ZnO NRs) are explored for the first time in ultraviolet (UV) photodetector (PD) that offers an outstanding self-powered photoresponse towards low UV illumination signals. A self-powered Cl-ZnO NRs PD exhibits superior photon detection speed of the order of a few ms with high sensitivity and photoelasticity. Therefore, the presented PD opens up a novel route to fabricate highly efficient self-powered PDs on a large scale without employing complex multilayer systems...
March 20, 2017: Nanoscale
Guang Qin Gu, Chang Bao Han, Jing Jing Tian, Cun Xin Lu, Chuan He, Tao Jiang, Zhou Li, Zhong Lin Wang
As a green and eco-friendly technology, triboelectric nanogenerator (TENG) can harvest energy from human motion to generate electricity, so TENGs have been widely applied in wearable electronic devices to replace traditional batteries. However, the surface of these TENGs is easily contaminated and breeds bacteria, which is a threat to human health. Here, we report an antibacterial composite film-based triboelectric nanogenerator (ACF-TENG) that uses Ag-exchanged zeolite (Ag-zeolite) and polypropylene (PP) composite film as the triboelectric layer...
March 27, 2017: ACS Applied Materials & Interfaces
Eduardo Ferreira da Costa, Nestor E de Oliveira, Flávio J O Morais, Pedro Carvalhaes-Dias, Luis Fernando C Duarte, Andreu Cabot, J A Siqueira Dias
We present here the design and fabrication of a self-powered and autonomous fringing field capacitive sensor to measure soil water content. The sensor is manufactured using a conventional printed circuit board and includes a porous ceramic. To read the sensor, we use a circuit that includes a 10 kHz triangle wave generator, an AC amplifier, a precision rectifier and a microcontroller. In terms of performance, the sensor's capacitance (measured in a laboratory prototype) increases up to 5% when the volumetric water content of the porous ceramic changed from 3% to 36%, resulting in a sensitivity of S = 15...
March 12, 2017: Sensors
Songfang Zhao, Jinhui Li, Duxia Cao, Guoping Zhang, Jia Li, Kui Li, Yang Yang, Wei Wang, Yufeng Jin, Rong Sun, Ching-Ping Wong
Stretchable and flexible sensors attached onto the surface of human body can perceive external stimuli, thus attracting extensive attention due to their lightweight, low modulus, low cost, high flexibility, and stretchability. Recently, a myriad of efforts have been devoted to improve the performance and functionality of wearable sensors. Herein, this reviews focuses on recent remarkable advancements in the development of flexible and stretchable sensors. Multifunction of these wearable sensors is realized by incorporating some desired features (e...
March 10, 2017: ACS Applied Materials & Interfaces
Gul Hassan, Fasihullah Khan, Arshad Hassan, Shawkat Ali, Jinho Bae, Chong Hyun Lee
Recently, many researchers are paying attention to nanogenerators (NGs) as energy source in self-powered mirco-nano system, and studying how to achieve their higher power generation. Hence, we propose a hybrid type NG harvesting both piezoelectric and triboelectric effect at the same time. In the proposed hybrid NG, the piezoelectric NG (PNG) and triboelectric NG (TENG) are fabricated by Polydimethylsiloxane (PDMS) and perovskite Zinc stannite (ZnSnO<sub>3</sub>) nano cubes with a high charge polarization of 59 uC/cm<sup>2</sup> composite (PDMS+ZnSnO<sub>3</sub>) and UV surface treated PDMS, respectively...
March 9, 2017: Nanotechnology
Narendar Gogurla, Subhas C Kundu, Samit K Ray
Silk protein has been used as a biopolymer substrate for flexible photonic devices. Here, we demonstrate ZnO nanorod array hybrid photodetectors on Au nanoparticle-embedded silk protein for flexible optoelectronics. Hybrid samples exhibit optical absorption at the band edge of ZnO as well as plasmonic energy due to Au nanoparticles, making them attractive for selective UV and visible wavelength detection. The device prepared on Au-silk protein shows a much lower dark current and a higher photo to dark-current ratio of ∼10(5) as compared to the control sample without Au nanoparticles...
April 7, 2017: Nanotechnology
Davide Brivio, Earl Ada, Erno Sajo, Piotr Zygmanski
We studied the effective contact potential difference (ECPD) of thin film nanostructures and its role in self-powered X-ray sensors, which use the high-energy current detection scheme. We compared the response to kilovoltage X-rays of several nanostructures made of disparate combinations of conductors (Al, Cu, Ta, ITO) and oxides (SiO2, Ta2O5, Al2O3). We measured current-voltage curves in parallel-plate configuration separated by an air gap and determined three characteristic parameters: current at zero voltage bias I0, the voltage offset for zero current ECPD, and saturation current Isat...
March 29, 2017: ACS Applied Materials & Interfaces
Shuo Chen, Xuemei Liu, Xvsheng Qiao, Xia Wan, Khurram Shehzad, Xianghua Zhang, Yang Xu, Xianping Fan
An effective colloidal process involving the hot-injection method is developed to synthesize uniform nanoflowers consisting of 2D γ-In2 Se3 nanosheets. By exploiting the narrow direct bandgap and high absorption coefficient in the visible light range of In2 Se3 , a high-quality γ-In2 Se3 /Si heterojunction photodiode is fabricated. This photodiode shows a high photoresponse under light illumination, short response/recovery times, and long-term durability. In addition, the γ-In2 Se3 /Si heterojunction photodiode is self-powered and displays a broadband spectral response ranging from UV to IR with a high responsivity and detectivity...
March 7, 2017: Small
Jingda Wu, Lih Y Lin
Conventional approaches to flexible optoelectronic devices typically require depositing the active materials on external substrates. This is mostly due to the weak bonding between individual molecules or nanocrystals in the active materials, which prevents sustaining a freestanding thin film. Herein we demonstrate an ultrathin freestanding ZnO quantum dot (QD) active layer with nanocellulose structuring, and its corresponding device fabrication method to achieve substrate-free flexible optoelectronic devices...
March 7, 2017: Scientific Reports
Hanyong Peng, Xing-Fang Li, Hongquan Zhang, X Chris Le
Synthetic DNA motors have great potential to mimic natural protein motors in cells but the operation of synthetic DNA motors in living cells remains challenging and has not been demonstrated. Here we report a DNAzyme motor that operates in living cells in response to a specific intracellular target. The whole motor system is constructed on a 20 nm gold nanoparticle (AuNP) decorated with hundreds of substrate strands serving as DNA tracks and dozens of DNAzyme molecules each silenced by a locking strand. Intracellular interaction of a target molecule with the motor system initiates the autonomous walking of the motor on the AuNP...
March 6, 2017: Nature Communications
Manuel Rivera, Rafael Velázquez, Ali Aldalbahi, Andrew F Zhou, Peter Feng
We extend our work on the use of digitally controlled pulsed laser plasma deposition (PLPD) technique to synthesize high quality, 2-dimensional single crystalline boron nitride nanosheets (BNNSs) at a low substrate temperature for applications in high-performance deep UV photodetectors. The obtained sample consists of a large amount of BNNSs partially overlapping one another with random orientations. Each sheet is composed of a few (from 2 to 10) stacked atomic layers exhibiting high transparency due to its highly ordered hBN crystallinity...
March 3, 2017: Scientific Reports
Qian Zhang, Qijie Liang, Qingliang Liao, Fang Yi, Xin Zheng, Mingyuan Ma, Fangfang Gao, Yue Zhang
Triboelectric nanogenerators (TENGs) or TENG-based self-charging systems harvesting energy from ambient environment are promising power solution for electronics. The stable running remains a key consideration in view of potential complex application environment. In this work, a textile-based tailorable multifunctional TENG (T-TENG) is developed. The T-TENG is used as self-powered human body motion sensor, water energy harvester, and formed all textile-based flexible self-charging system by integrating with textile-based supercapacitors...
March 1, 2017: Advanced Materials
Josman P Pérez-Expósito, Tiago M Fernández-Caramés, Paula Fraga-Lamas, Luis Castedo
This article presents VineSens, a hardware and software platform for supporting the decision-making of the vine grower. VineSens is based on a wireless sensor network system composed by autonomous and self-powered nodes that are deployed throughout a vineyard. Such nodes include sensors that allow us to obtain detailed knowledge on different viticulture processes. Thanks to the use of epidemiological models, VineSens is able to propose a custom control plan to prevent diseases like one of the most feared by vine growers: downy mildew...
February 25, 2017: Sensors
Li Duan, Fengni He, Ye Tian, Bin Sun, Jibin Fan, Xiaochen Yu, Lei Ni, Yan Zhang, Yongnan Chen, Wenxue Zhang
A Schottky UV photodetector based on graphene/ZnO:Al nanorod-array-film (AZNF) structure has been fabricated. Different from the previously reported graphene/ZnO photodetectors, this photodetector has a stable Schottky barrier which does not disappear under UV light. Thus, the UV photodetector can work as a high-performance self-powered device. The key to improve the stability of the Schottky barrier is a two-step surface treatment process. As a result, the self-powered photodetector exhibits a UV-to-visible rejection ratio of about 1 × 10(2), a responsivity of 0...
February 27, 2017: ACS Applied Materials & Interfaces
Panpan Gai, Chengcheng Gu, Ting Hou, Feng Li
Herein, we reported a novel ultrasensitive one-compartment enzyme biofuel cells (EBFCs)-based self-powered aptasensing platform for antibiotic residue detection. By taking full advantage of the unique features of both EBFCs-based self-powered sensors and aptamers, the as-proposed aptasensing platform has the merits of simple instrumentation, anti-interference ability, high selectivity, and low cost. In this study, DNA bioconjugate, i.e., SiO2@gold nanoparticles-complementary strand of aptamer (SiO2@AuNPs-csDNA), was elaborately designed and played a key role in blocking the mass transport of glucose to the bioanode...
February 7, 2017: Analytical Chemistry
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