scholarly journals Pencil–paper on-skin electronics

2020 ◽  
Vol 117 (31) ◽  
pp. 18292-18301 ◽  
Author(s):  
Yadong Xu ◽  
Ganggang Zhao ◽  
Liang Zhu ◽  
Qihui Fei ◽  
Zhe Zhang ◽  
...  

Pencils and papers are ubiquitous in our society and have been widely used for writing and drawing, because they are easy to use, low-cost, widely accessible, and disposable. However, their applications in emerging skin-interfaced health monitoring and interventions are still not well explored. Herein, we report a variety of pencil–paper-based on-skin electronic devices, including biophysical (temperature, biopotential) sensors, sweat biochemical (pH, uric acid, glucose) sensors, thermal stimulators, and humidity energy harvesters. Among these devices, pencil-drawn graphite patterns (or combined with other compounds) serve as conductive traces and sensing electrodes, and office-copy papers work as flexible supporting substrates. The enabled devices can perform real-time, continuous, and high-fidelity monitoring of a range of vital biophysical and biochemical signals from human bodies, including skin temperatures, electrocardiograms, electromyograms, alpha, beta, and theta rhythms, instantaneous heart rates, respiratory rates, and sweat pH, uric acid, and glucose, as well as deliver programmed thermal stimulations. Notably, the qualities of recorded signals are comparable to those measured with conventional methods. Moreover, humidity energy harvesters are prepared by creating a gradient distribution of oxygen-containing groups on office-copy papers between pencil-drawn electrodes. One single-unit device (0.87 cm2) can generate a sustained voltage of up to 480 mV for over 2 h from ambient humidity. Furthermore, a self-powered on-skin iontophoretic transdermal drug-delivery system is developed as an on-skin chemical intervention example. In addition, pencil–paper-based antennas, two-dimensional (2D) and three-dimensional (3D) circuits with light-emitting diodes (LEDs) and batteries, reconfigurable assembly and biodegradable electronics (based on water-soluble papers) are explored.

2016 ◽  
Vol 2 (6) ◽  
pp. e1501624 ◽  
Author(s):  
Fang Yi ◽  
Xiaofeng Wang ◽  
Simiao Niu ◽  
Shengming Li ◽  
Yajiang Yin ◽  
...  

The rapid growth of deformable and stretchable electronics calls for a deformable and stretchable power source. We report a scalable approach for energy harvesters and self-powered sensors that can be highly deformable and stretchable. With conductive liquid contained in a polymer cover, a shape-adaptive triboelectric nanogenerator (saTENG) unit can effectively harvest energy in various working modes. The saTENG can maintain its performance under a strain of as large as 300%. The saTENG is so flexible that it can be conformed to any three-dimensional and curvilinear surface. We demonstrate applications of the saTENG as a wearable power source and self-powered sensor to monitor biomechanical motion. A bracelet-like saTENG worn on the wrist can light up more than 80 light-emitting diodes. Owing to the highly scalable manufacturing process, the saTENG can be easily applied for large-area energy harvesting. In addition, the saTENG can be extended to extract energy from mechanical motion using flowing water as the electrode. This approach provides a new prospect for deformable and stretchable power sources, as well as self-powered sensors, and has potential applications in various areas such as robotics, biomechanics, physiology, kinesiology, and entertainment.


2021 ◽  
Vol 13 (22) ◽  
pp. 12807
Author(s):  
Md Fahim Tanvir Hossain ◽  
Samer Dessouky ◽  
Ayetullah B. Biten ◽  
Arturo Montoya ◽  
Daniel Fernandez

This study aims at designing and developing a new technique to harvest solar energy from asphalt pavements. The proposed energy harvester system consists of a pavement solar box with a transparent polycarbonate sample and a thin-film solar panel. This device mechanism can store energy in a battery charged over daytime and later convert it into electric power as per demand. A wide range of polycarbonate samples containing different thicknesses, elastic moduli, and light transmission properties were tested to select the most efficient materials for the energy harvester system. Transmittance Spectroscopy was conducted to determine the percent light transmission property of the polycarbonate samples at different wavelengths in the visible spectrum. Finite Element Analysis modeling of the pavement–tire load system was conducted to design the optimal energy harvester system under static load. It was followed by the collection of data on the generated power under different weather conditions. The energy harvesters were also subjected to vehicular loads in the field. The results suggest that the proposed pavement solar box can generate an average of 23.7 watts per square meter continuously over 6 h a day under sunny conditions for the weather circumstances encountered in South Texas while providing a slightly smaller power output in other weather circumstances. It is a promising self-powered and low-cost installation technique that can be implemented at pedestrian crossings and intersections to alert distracted drivers at the time of pedestrian crossing, which is likely to improve pedestrian safety.


2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Nidhi Mathur ◽  
Anamika Aneja ◽  
P. K. Bhatnagar ◽  
P. C. Mathur

A reliable, fast, and low-cost biosensor for medical diagnostics using DNA sequence detection has been developed and tested for the detection of the bacterium “Bacillus anthracis.” In this sensor, Poly [9,9-di (6,6′- N,N′trimethylammonium) hexylfluorenyl-2, 7-diyl)-alt-co- (1,4-phenylene)] dibromide salt (PFP) has been taken as cationic conjugated polymer (CCP) and PNA attached with fluorescein dye (PNAC∗) as a probe. The basic principle of this sensor is that when aPNAC∗probe is hybridized with a single strand DNA (ssDNA) having complementary sequence, Forster resonance energy transfer (FRET) may take place from PFP to thePNAC∗/DNA complex. If the FRET is efficient, the photoluminescence from the PFP will be highly quenched and that fromPNAC∗will be enhanced. On the other hand, if the DNA sequence is noncomplementary to PNA, FRET will not occur.


2022 ◽  
pp. 004051752110698
Author(s):  
Chuanli Su ◽  
Guangwei Shao ◽  
Qinghua Yu ◽  
Yaoli Huang ◽  
Jinhua Jiang ◽  
...  

Highly conductive, flexible, stretchable and lightweight electrode substrates are essential to meet the future demand on supercapacitors for wearable electronics. However, it is difficult to achieve the above characteristics simultaneously. In this study, ultrafine stainless-steel fibers (with a diameter of ≈30 μm) are knitted into stainless-steel meshes (SSMs) with a diamond structure for the fabrication of textile stretchable electrodes and current collectors. The electrodes are fabricated by utilizing an electrodeposited three-dimensional network graphene framework and poly(3,4-ethylenedioxythiophene) (PEDOT) coating on the SSM substrates via a two-step electrodeposition process, which show a specific capacitance of 77.09 F g−1 (0.14 A g−1) and superb cycling stability (91% capacitance retention after 5000 cycles). Furthermore, the assembled flexible stretchable supercapacitor based on the PEDOT/reduced graphene oxide (RGO)@SSM electrodes exhibits an areal capacitance (53 mF cm−2 at 0.1 mA cm−2), a good cycling stability (≈73% capacitance retention after 5000 cycles), rate capability (36 mF cm−2 at 5 mA cm−2), stretchable stability (≈78% capacitance retention at 10% strain for 500 stretching cycles) and outstanding flexibility and stability under various bending deformations. The assembled supercapacitors can illuminate a thermometer and a light-emitting diode, demonstrating their potential application as stretchable supercapacitors. This simple and low-cost method developed for fabricating lightweight, stretchable and stable high-performance supercapacitors offers new opportunities for future stretchable electronic devices.


2014 ◽  
Vol 50 (16) ◽  
pp. 1947 ◽  
Author(s):  
Yanhu Wang ◽  
Lei Ge ◽  
Panpan Wang ◽  
Mei Yan ◽  
Jinghua Yu ◽  
...  

2017 ◽  
Vol 5 (4) ◽  
Author(s):  
Hongbo Lan

Multiscale and multimaterial three-dimensional (3D) printing is new frontier in additive manufacturing (AM). It has shown great potential to implement the simultaneous and full control for fabricated object including external geometry, internal architecture, functional surface, material composition and ratio as well as gradient distribution, feature size ranging from nano-, micro-, to macro-scale, embedded components and electrocircuit, etc. Furthermore, it has the ability to construct the heterogeneous and hierarchical structured object with tailored properties and multiple functionalities which cannot be achieved through the existing technologies. That paves the way and may result in great breakthrough in various applications, e.g., functional tissue and organ, functionally graded (FG) material/structure, wearable devices, soft robot, functionally embedded electronics, metamaterial, multifunctionality product, etc. However, very few of the established AM processes have now the capability to implement the multimaterial and multiscale 3D printing. This paper presented a single nozzle-based multiscale and multimaterial 3D printing process by integrating the electrohydrodynamic jet printing and the active mixing multimaterial nozzle. The proposed AM technology has the capability to create multifunctional heterogeneously structured objects with control of the macroscale external geometry and microscale internal structures as well as functional surface features, particularly, the potential to dynamically mix, grade, and vary the ratios of different materials. An active mixing nozzle, as a core functional component of the 3D printer, is systematically investigated by combining with the theoretical analysis, numerical simulation, and experimental verification. The study aims at exploring a feasible solution to implement the multiscale and multimaterial 3D printing at low cost.


2009 ◽  
Vol 1197 ◽  
Author(s):  
Jun Takeya ◽  
M. Uno ◽  
Kengo Nakayama

AbstractAttractiveness of organic field-effect transistors are in their low-cost and easy fabrication processes as well as their mechanical flexibility, while a significant drawback has been their poorer transistor performances than those of silicon and oxide semiconductors because of lower carrier mobility in organic semiconductors. We have developed an easy MEMS-based process to fabricate three-dimensional organic transistors with metal-insulator-semiconductor structures of multiple vertical channels on plastic platforms. The design maximizes the space availability and the output current per area. The flexible three-dimensional organic transistors indeed present outstanding current of ∼ 0.5 A/cm2, which is more than sufficient for driving pixels of typical organic light-emitting diodes. High on-off ratio up to 107 is also demonstrated.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xiaolin Sun ◽  
Ting Zhang ◽  
Linwei Yu ◽  
Ling Xu ◽  
Junzhuan Wang

AbstractIn this work, three-dimensional (3D) radial heterojunction photodetectors (PD) were constructed over vertical crystalline Si nanowires (SiNWs), with stacked hydrogenated amorphous germanium (a-Ge:H)/a-Si:H thin film layer as absorbers. The hetero absorber layer is designed to benefit from the type-II band alignment at the a-Ge/a-Si hetero-interface, which could help to enable an automated photo-carrier separation without exterior power supply. By inserting a carefully controlled a-Si passivation layer between the a-Ge:H layer and the p-type SiNWs, we demonstrate first a convenient fabrication of a new hetero a-Ge/a-Si structure operating as self-powered photodetectors (PD) in the near-infrared (NIR) range up to 900 nm, indicating a potential to serve as low cost, flexible and high performance radial junction sensing units for NIR imaging and PD applications.


2015 ◽  
Vol 43 (2) ◽  
pp. 117-143 ◽  
Author(s):  
Boren Li ◽  
Tomonari Furukawa

ABSTRACT This paper presents the design and development of a stationary microtexture road profiling system using the photometric stereo (PS) technique. The structure of the developed system is simple, mainly consisting of a digital single-lens reflex (DSLR) camera with a macro lens and multiple light-emitting diodes (LEDs). The camera with the lens is oriented perpendicularly to the pavement texture and takes images each with a different LED turned on at a time. With the pavement texture images with diverse shadings, the PS technique is applied by inverting the image-forming process locally (pixel-wise) to associate the measured image intensities with the known lighting directions to estimate the gradients for each pixel-corresponding surface patch of the pavement texture. Surface normal integration (SNI) is then employed to reconstruct the three-dimensional (3D) road surface in the microtexture scale. The PS-based system has several intrinsic advantages. First, it could achieve high accuracy for surfaces with most diffuse reflection. Second, the measurement speed is fast because of its area-scanning nature. Third, the spatial resolution is high because of the usage of a high-resolution complementary metal-oxide semiconductor DSLR camera. In addition, it can be less sensitive to effects from specularities and shadows compared with most optical-based methods, since images captured under diverse lighting directions in PS provide more cues for detection purposes. Last but not least, the hardware of the system can be made compact at low cost because of its simple structure and can be adapted for direct measurement on the pavement. Parametric studies for the Lambertian-based PS technique were first investigated analytically and numerically, and these investigations yielded the design of the system having eight LEDs with the same zenith angle of 30 degrees and uniformly distributed azimuth angles in 360 degrees. Several experimental results on various types of surfaces have demonstrated that the developed system could achieve the accuracy in the order of 10 microns.


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