Continuous Process for Large-Area Flexible MEMS

2012 ◽  
Vol 81 ◽  
pp. 9-14
Author(s):  
Toshihiro Itoh
Keyword(s):  
High Speed ◽  
Spray Deposition ◽  
Continuous Process ◽  
Electrical Contact ◽  
Functional Materials ◽  
Micro Machining ◽  
Large Area ◽  
Conductive Films ◽  
Touch Sensor ◽  
Process System

A novel fabrication process for large area flexible MEMS, having been developed in BEANS project, Japan, is introduced. The process consists of continuously high-speed coating for functional film materials, 3-D nano/micro-machining of the films on fibers, and weaving the functional fibers into large-area integration. In the coating process, functional materials, e.g., organic semiconductor, piezoelectric, conductor and insulator films could be formed on fibers with a speed of 20 m/min. In the 3-D nano/micro-machining, a compound reel-to-reel process system including both thermal roller imprint and photolithography functions was developed. In addition, the microfabrication of the 3-D exposure module and the spray deposition of thin resist films on the fibers were demonstrated. For the weaving assembly, a round-projection microspring contact structure was developed for the electrical contact between weft and warp fibers in a large area of woven textile. Evaluation of the durability showed that the microspring contact structures made of silicon elastomer and PEDOT:PSS are applicable to a movable contact. Weaving assembly process was verified by prototyping 1 × 1 m² or larger flexible touch sensor sheets using functional fibers with organic insulating/conductive films.

scholarly journals Graphene Nanoflakes Incorporating Natural Phytochemicals Containing Catechols as Functional Material for Sensors

2021 ◽  
Vol 5 (1) ◽  
pp. 14
Author(s):  
Filippo Silveri ◽  
Flavio Della Pelle ◽  
Daniel Rojas ◽  
Dario Compagnone
Keyword(s):  
Electrical Contact ◽  
Functional Materials ◽  
High Sensitivity ◽  
Cost Effective ◽  
Water Soluble ◽  
Intrinsic Conductivity ◽  
Conductive Films ◽  
Graphene Nanoflakes ◽  
Conventional Surfactant ◽  
2D Nanomaterials

Phytochemical products start to be employed to assist 2D nanomaterials exfoliation. However, a lack of studies regarding the molecules involved and their capacity to give rise to functional materials is evident. In this work, a novel green liquid-phase exfoliation strategy (LPE) is proposed, wherein a flavonoid namely catechin (CT) exclusively assists the exfoliation of bulk graphite in conductive water-soluble graphene nanoflakes (GF). Physicochemical and electrochemical methods have been employed to characterize the morphological, structural, and electrochemical features of the GF-CT. Surprisingly, the obtained GF-CT integrates well-defined electroactive quinoid adducts. The resulting few-layers graphene flakes intercalated with CT aromatic skeleton ensure strict electrical contact among graphene sheets, whereas the fully reversible quinoid electrochemistry (ΔE = 28 mV, Ip, a/Ip, c = ~1) is attributed to the residual catechol moieties, which work as an electrochemical mediator. The GF-CT intimate electrochemistry is generated directly during the LPE of graphite, not requiring any modification or electro-polymerization steps, resulting in stable (8 months) and reproducible material. The electrocatalytic activity has been proven towards hydrazine (HY) and β-nicotinamide adenine dinucleotide (NADH), a pollutant and a coenzyme, respectively. High sensitivity in extended linear ranges (HY: LOD = 0.1 µM, L.R. 0.5–150 µM; NADH: LOD = 0.6 µM, L.R. 2.5–200 µM) at low overpotential (+0.15 V) was obtained using amperometry, avoiding electrode-fouling. Improved performances, compared with graphite commercial electrodes and graphene exfoliated with a conventional surfactant, were obtained. The GF-CT was successfully used to perform the detection of HY and NADH (recoveries 94–107%, RSD ≤ 8%) in environmental and biological matrices, proving the material exploitability even in challenging analytical applications. On course studies aim to combine the intrinsic conductivity of the GF-CT with flexible substrates, in order to construct flexible electrodes/devices able to house GF-CT-exclusively composed conductive films. In our opinion, the proposed GF-CT elects itself as a cost-effective and sustainable material, particularly captivating in the (bio)sensoristics scenario.

scholarly journals Theoretical Uniformity Analysis and Improvement of Spray Deposition by Mixing Nozzles with Heating Conditions

Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 81
Author(s):  
Xuran Dong ◽  
Xiaolong Pan ◽  
Xianxian Gao ◽  
Haisheng Fang
Keyword(s):  
High Speed ◽  
Heating Temperature ◽  
Spray Deposition ◽  
Low Cost ◽  
Spray Coating ◽  
Deposition Process ◽  
Test Method ◽  
Large Area ◽  
Orthogonal Test Method ◽  
Experimental Trials

Spray coating is widely used in the manufacture of deposited layers of electronic devices due to its unique advantages of high-speed deposition over a large area. To improve the spray deposition process for further low-cost and uniform production, the uniformity of the spray deposition should be systematically investigated. The current study, however, mainly focuses on the experimental trials with few numerical directions especially for the mixing nozzle sprayers with heating conditions. In the paper, we conduct a theoretical study on the uniformity of the internal and external mixing nozzles. The influencing factors include the initial angle, the total ink flow rate, the transporting gas velocity and the distance from the nozzle to the substrate. Then, the orthogonal test method is adopted to obtain the optimal combination of the parameters. Finally, the effects of different heating modes on the uniformity have been further studied. The results show that these factors influence the uniformity with the two types of nozzles to a different degree. The evaporation of the atomized droplets can effectively improve the uniformity in a certain temperature range. The heating temperature with the highest uniformity is various depending on the heating modes, which should be carefully addressed during the actual production.

scholarly journals High-speed high-efficiency large-area resonant cavity enhanced p-i-n photodiodes for multimode fiber communications

2001 ◽  
Vol 13 (12) ◽  
pp. 1349-1351 ◽  
Author(s):  
M. Gokkavas ◽  
O. Dosunmu ◽  
M.S. Unlu ◽  
G. Ulu ◽  
R.P. Mirin ◽  
...  
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
Resonant Cavity ◽  
Multimode Fiber ◽  
Large Area ◽  
Fiber Communications

An Investigation onto Polydimethylsiloxane (PDMS) Printing Plate of Multiple Functional Solid Line by Flexographic

2013 ◽  
Vol 844 ◽  
pp. 158-161 ◽  
Author(s):  
M.I. Maksud ◽  
Mohd Sallehuddin Yusof ◽  
M. Mahadi Abdul Jamil
Keyword(s):  
Laser Ablation ◽  
Line Width ◽  
High Speed ◽  
Printed Electronics ◽  
Low Cost ◽  
Flexible Substrates ◽  
Large Area ◽  
Printing Plate ◽  
Roll To Roll ◽  
Printing Processes

Recently low cost production is vital to produce printed electronics by roll to roll manufacturing printing process like a flexographic. Flexographic has a high speed technique which commonly used for printing onto large area flexible substrates. However, the minimum feature sizes achieved with roll to roll printing processes, such as flexographic is in the range of fifty microns. The main contribution of this limitation is photopolymer flexographic plate unable to be produced finer micron range due to film that made by Laser Ablation Mask (LAMs) technology not sufficiently robust and consequently at micron ranges line will not be formed on the printing plate. Hence, polydimethylsiloxane (PDMS) is used instead of photopolymer. Printing trial had been conducted and multiple solid lines successfully printed for below fifty microns line width with no interference between two adjacent lines of the printed images.

scholarly journals Diffuse Coplanar Surface Barrier Discharge in Artificial Air: Statistical Behaviour of Microdischarges

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Jan Čech ◽  
Jana Hanusová ◽  
Pavel Sťahel ◽  
Mirko Černák
Keyword(s):  
High Speed ◽  
Barrier Discharge ◽  
Atmospheric Pressure Plasma ◽  
Input Voltage ◽  
Half Period ◽  
Surface Barrier ◽  
Electrical Measurements ◽  
Large Area ◽  
Electrode Gap ◽  
Surface Barrier Discharge

AbstractDiffuse Coplanar Surface Barrier Discharge (DCSBD) is a novel type of atmospheric-pressure plasma source developed for high-speed large-area surface plasma treatments. The statistical behavior of microdischarges of DCSBD generated in artificial air atmosphere was studied using time-correlated optical and electrical measurements. Changes in behavior of microdischarges are shown for various electrode gap widths and input voltage amplitudes. They are discussed in the light of correlation of the number of microdischarges and the number of unique microdischarges’ paths per discharge event.The ‘memory effect’ was observed in the behavior of microdischarges and it manifests itself in a significant number of microdischarges reusing the path of microdischarges from previous half-period. Surprisingly this phenomenon was observed even for microdischarges of the same half-period of the discharge, where mechanisms other than charge deposition have to be involved. The phenomenon of discharge paths reuse is most pronounced for wide electrode

scholarly journals Spray deposition inside multiple-row nursery trees with a laser-guided sprayer1

2017 ◽  
Vol 35 (1) ◽  
pp. 13-23 ◽  
Author(s):  
H. Zhu ◽  
H. Liu ◽  
Y. Shen ◽  
Hengyu Liu ◽  
R. H. Zondag
Keyword(s):  
High Speed ◽  
Laser Scanning ◽  
Quercus Rubra ◽  
Spray Deposition ◽  
Field Tests ◽  
Red Oak ◽  
Northern Red Oak ◽  
Tree Structures ◽  
Speed Sensor ◽  
Tilia Tomentosa

Abstract Multiple-row container-grown trees require specially designed sprayers to achieve efficient spray delivery. A five-port air-assisted sprayer with both automatic and manual control modes was developed to discharge adequate spray deposition inside multiple-row trees. The sprayer resulted from integration of a high-speed laser-scanning sensor with a sophisticated nozzle flow control system, an embedded computer with a touch screen, a Doppler speed sensor, a specially-designed algorithm and an air-assisted sprayer base. It was able to detect target tree presence and measure target tree size, shape and leaf density. The sprayer then controlled the spray output of each nozzle to match tree structures. The sprayer was tested for its sprayer deposition quality inside canopies in a four-row sterling silver linden (Tilia tomentosa 'Sterling Silver' Moench) field and another six-row northern red oak (Quercus rubra L.) field. Tests were conducted with the sprayer in variable-rate application (VRA) and constant-rate application (CRA) modes. The average spray deposit on foliage of trees was 1.37±0.47 μL cm−2 from VRA and 1.29±0.42 μL cm−2 from CRA in linden, and was 2.15±0.57 μL cm−2 from VRA and 2.72±0.94 μL cm−2 from CRA in red oak, respectively. In comparison, spray coverage on foliage of trees was 19.8±3.0% from VRA and 20.9±4.3% from CRA in the linden trial, and was 27.9±3.7% from VRA and 30.5±5.4% from CRA, respectively, in the red oak trial. The newly developed air-assisted sprayer in both VRA and CRA modes would be able to discharge adequate spray deposition inside multiple-row tree plants while conserving pesticide. Index words: environmental protection, pest control, pesticide, precision sprayer, spray coverage. Species used in this study: sterling silver linden (Tilia tomentosa 'Sterling Silver' Moench), northern red oak (Quercus rubra L.).

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