scholarly journals Development of a Strain Sensor Matrix on Mobilized Flexible Substrate for the Imaging of Wind Pressure Distribution

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 232 ◽  
Author(s):  
Shusuke Kanazawa ◽  
Hirobumi Ushijima
Keyword(s):  
Pressure Distribution ◽  
Flexible Electronics ◽  
Screen Printing ◽  
Flexible Substrate ◽  
Strain Sensor ◽  
Wind Pressure ◽  
Device Structure ◽  
Flexible Sensor ◽  
The Matrix ◽  
Suspended Structure

This paper presents a novel flexible sensor for monitoring wind pressure distribution. Based on the concept of “flexible mechatronics”, a suspended structure was incorporated into the matrix of a resistive-strain sensor in a plastic film to make the sensor mechanically movable against the wind. Screen printing and laser cutting were confirmed to be satisfactory methods for fabricating the proposed device structure. As a result, the visualization of wind pressure was successfully demonstrated by the fabricated sensor sheet and an imaging-display-creation software. The results of this study show that a mechanically functionalized substrate opens up new avenues for flexible electronics.

Screen Printing Fine Pitch Stretchable Silver Inks onto a Flexible Substrate for Wearable Applications

2018 ◽  
Vol 2018 (1) ◽  
pp. 000665-000671
Author(s):  
Jianbiao Pan ◽  
Malcolm Keif ◽  
Joshua Ledgerwood ◽  
Xiaoying Rong ◽  
Xuan Wang
Keyword(s):  
Sheet Resistance ◽  
Flexible Electronics ◽  
Screen Printing ◽  
Flexible Substrate ◽  
Thermoplastic Polyurethane ◽  
Organic Substrate ◽  
Printing Process ◽  
Silver Ink ◽  
Fine Pitch

Abstract The lightweight and bendable features of printed flexible electronics are increasingly attractive. Currently stretchable silver inks are formulated for wide traces, typically larger than 2 mm. To attach ultra-thin silicon chips that have fine pitch onto printed organic substrate, it is necessary to print fine trace width/space that matches the pitch of the chips, which may be less than 200 microns. This paper presents the development and optimization of the screen printing process for printing stretchable silver ink onto stretchable thermoplastic polyurethane (TPU) substrate. A test vehicle was designed including 50 μm/5 mm (line width/line length) to 350 μm/35 mm lines (at 4 biases). The stretchable ink selected was DuPont PE 873 and Dupont's PE 5025 ink (non-stretchable conductive flake silver) was used as a “control” to baseline the printing process. The substrate used was Bemis TPU ST604. The experiment was done on a DEK Horizon 03i printer. A DEK squeegee 200 (Blue) and a DEK 265 flood bar (200 mm) were used. A 2-level factorial design with three replicates was selected to investigate the effect of process parameters on the quality of prints. The quality of the prints is characterized by 1) resistance of traces, 2) sheet resistance, 3) z-axis height, and 4) trace width/spacing. We observed significant noise in the z-axis printed silver ink height measured by profilometry and concluded z-axis height is not a good response variable for characterizing screen printing stretchable silver ink onto TPU substrate, mainly due to high roughness of the TPU substrate. We proposed calculated sheet resistance based on the measured resistance value, trace width, and trace length, which can replace trace height measurements on rough profile substrates. We found that squeegee pressure and emulsion thickness have statistically significant effects on calculated sheet resistance of print traces while print speed does not have statistically significant effects. In our experiment setting levels, the lower the squeegee pressure, the lower the calculated sheet resistance that is achieved. The emulsion with higher emulsion over mesh (EOM) is better than the emulsion with lower EOM since it can achieve lower sheet resistance. After optimizing the screen printing process, we were able to print 100 μm (4 mils) trace width and spacing with high consistency.

scholarly journals Strain Sensor Based on Biological Nanomaterial

2021 ◽  
Vol 6 (1) ◽  
pp. 23
Author(s):  
Levan P. Ichkitidze ◽  
Alexander Yu. Gerasimenko ◽  
Dmitry V. Telyshev ◽  
Eugeny P. Kitsyuk ◽  
Vladimir A. Petukhov ◽  
...  
Keyword(s):  
Screen Printing ◽  
Respiratory Diseases ◽  
Specific Conductivity ◽  
Strain Sensor ◽  
Aqueous Dispersion ◽  
Strain Sensors ◽  
Bending Angle ◽  
Multi Walled Carbon Nanotubes ◽  
Number Of Cycles ◽  
Walled Carbon Nanotubes

We investigated a prototype of a strain sensor based on the layers of a bionanomaterial containing bovine serum albumin (BSA matrix) and multi-walled carbon nanotubes (MWCNT filler). The aqueous dispersion of 25 wt.% BSA/0.3 wt.% MWCNT was applied by screen printing onto flexible polyethylene terephthalate substrates. After drying the layers by laser irradiation (~970 nm), various parameters of the layers were controlled, i.e., resistance R, bending angle θ, number of cycles n, and measurement time. One measurement cycle corresponded to a change within the range θ = ±150°. The layers of the BSA/MWCNT bionanomaterial had dimensions of (15 ÷ 20) mm × (8 ÷ 10) mm × (0.5 ÷ 1. 5) µm. The dependences of resistance R on the bending angle θ were similar for all layers at θ = ±30, and the R(θ) curves represented approximate linear dependences (with an error of ≤ 10%); beyond this range, the dependences became nonlinear. The following quantitative values were obtained for the investigated strain sensor: specific conductivity ~1 ÷ 10 S/m, linear strain sensitivity ~160, and bending sensitivity 1.0 ÷ 1.5%/°. These results are high. The examined layers of the bionanomaterial BSA/MWCNT as a strain sensor are of particular interest for medical practice. In particular, strain sensors can be implemented by applying a water dispersion of nanomaterials to human skin using a 3D printer for monitoring movements (arms and blinking) and the detection of signs of pathology (dysphagia, respiratory diseases, angina, etc.).

scholarly journals Fabrication of Piezoelectric ZnO Nanowires Energy Harvester on Flexible Substrate Coated with Various Seed Layer Structures

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1433
Author(s):  
Taoufik Slimani Tlemcani ◽  
Camille Justeau ◽  
Kevin Nadaud ◽  
Daniel Alquier ◽  
Guylaine Poulin-Vittrant
Keyword(s):  
Seed Layer ◽  
Layer Structure ◽  
Mechanical Energy ◽  
Flexible Substrate ◽  
Average Power ◽  
Electrical Characterization ◽  
Zno Nanowires ◽  
Device Structure ◽  
Layer Structures ◽  
Electrical Output

Flexible piezoelectric nanogenerators (PENGs) are very attractive for mechanical energy harvesting due to their high potential for realizing self-powered sensors and low-power electronics. In this paper, a PENG that is based on zinc oxide (ZnO) nanowires (NWs) is fabricated on flexible and transparent Polydimethylsiloxane (PDMS) substrate. The ZnO NWs were deposited on two different seed layer structures, i.e., gold (Au)/ZnO and tin-doped indium-oxide (ITO)/ZnO, using hydrothermal synthesis. Along with the structural and morphological analyses of ZnO NWs, the electrical characterization was also investigated for ZnO NWs-based flexible PENGs. In order to evaluate the suitability of the PENG device structure, the electrical output performance was studied. By applying a periodic mechanical force of 3 N, the ZnO NWs-based flexible PENG generated a maximum root mean square (RMS) voltage and average power of 2.7 V and 64 nW, respectively. Moreover, the comparison between the fabricated device performances shows that a higher electrical output can be obtained when ITO/ZnO seed layer structure is adopted. The proposed ZnO NWs-based PENG structure can provide a flexible and cost-effective device for supplying portable electronics.

scholarly journals Reliability-Aware SPICE Compatible Compact Modeling of IGZO Inverters on a Flexible Substrate

2021 ◽  
Vol 11 (11) ◽  
pp. 4838
Author(s):  
Je-Hyuk Kim ◽  
Youngjin Seo ◽  
Jun Tae Jang ◽  
Shinyoung Park ◽  
Dongyeon Kang ◽  
...  
Keyword(s):  
Flexible Electronics ◽  
Circuit Simulation ◽  
Flexible Substrate ◽  
Atomic Layer ◽  
Operating Conditions ◽  
Gate Insulator ◽  
Compact Modeling ◽  
Indium Gallium Zinc Oxide ◽  
Electrical Stress ◽  
Bending Radius

Accurate circuit simulation reflecting physical and electrical stress is of importance in indium gallium zinc oxide (IGZO)-based flexible electronics. In particular, appropriate modeling of threshold voltage (VT) changes in different bias and bending conditions is required for reliability-aware simulation in both device and circuit levels. Here, we present SPICE compatible compact modeling of IGZO transistors and inverters having an atomic layer deposition (ALD) Al2O3 gate insulator on a polyethylene terephthalate (PET) substrate. Specifically, the modeling was performed to predict the behavior of the circuit using stretched exponential function (SEF) in a bending radius of 10 mm and operating voltages ranging between 4 and 8 V. The simulation results of the IGZO circuits matched well with the measured values in various operating conditions. It is expected that the proposed method can be applied to process improvement or circuit design by predicting the direct current (DC) and alternating current (AC) responses of flexible IGZO circuits.

Preparation of Conductive Nanosilver Ink and its Application on RFID Tags

2014 ◽  
Vol 904 ◽  
pp. 121-125 ◽  
Author(s):  
Ji Lan Fu ◽  
Ya Ling Li ◽  
Li Xin Mo ◽  
Yu Wang ◽  
Jun Ran ◽  
...  
Keyword(s):  
Flexible Electronics ◽  
Screen Printing ◽  
Surface Resistance ◽  
Large Scale ◽  
Printed Electronics ◽  
Silver Content ◽  
Rfid Tags ◽  
Rheological Characteristics ◽  
Conductive Ink ◽  
New Type

The recent dramatic progress in the printed electronics and flexible electronics, due to the universality of the substrates including the foldable and stretchable substrates, has opened a new prospect in the field of future electronics. In this paper, silver nanospheres in large-scale are synthesized, the nanosilver ink with 63.88% silver content are prepared and a new type of highly conductive and far identify distance RFID tags are manufactured. Especially there are no resin and other additives containing in our conductive ink which satisfy the rheological characteristics and process of screen printing. The tags exhibit the best radiation performance own to there is no high temperature sintering in need. The surface resistance of the tags could be 80 mΩ/, and the identify distance reach to 6.0m. Keywords:silver nanoparticles, conductive ink, RFID tags

Largely Deformable and Highly Sensitive Strain Sensor Using Carbon Nanomaterials

2017 ◽  
Author(s):  
Kanji Yumoto ◽  
Ken Suzuki ◽  
Hideo Miura
Keyword(s):  
Aspect Ratio ◽  
Growth Condition ◽  
Electrical Resistance ◽  
Carbon Nanomaterials ◽  
Flexible Substrate ◽  
Strain Sensor ◽  
Sensitive Strain ◽  
Synthesis Process ◽  
Pressure Sensitivity ◽  
Highly Sensitive

A new type tactile sensor with spatial resolution less than 1 mm and the minimum pressure sensitivity less than 10 kPa was proposed by applying MWCNTs (Multi-Walled Carbon Nanotubes). The sensor was embedded into a highly deformable flexible substrate (PDMS: Polydimethylsiloxane) and the obtained gauge factor of the developed sensor was about 5. Since the electronic properties of MWCNTs vary drastically depending on their deformation under mechanical stress, it is important to make appropriate aspect ratio of MWCNTs for improving their stress-sensitivity. The aspect ratio of MWCNTs are mainly dominated by their growth condition such as the average thickness of catalyst layer, growth temperature, pressure of resource gases and so on. Thus, the optimum growth condition was investigated for forming the MWCNTs with high aspect ratio, in other words, high pressure sensitivity. In addition, in this study, the authors fabricated high quality carbon nano-materials to develop highly sensitive strain sensor. A thermal CVD synthesis process of MWCNTs was developed by using acetylene gas. After the synthesis of MWCNTs, flexible isolation material (PDMS) was coated around the grown MWCNT. Then, the interconnection film was deposited by sputtering. After that, PDMS was coated again to fabricate an upper protection layer. Finally, the bottom interconnection layer was sputtered and patterned. The change of the electrical resistance of the grown MWCNTs was measured by applying a compression test in the load range from 0 to 10 mN. It was found that the electrical resistance of the MWCNTs bundle increased almost linearly with the applied compressive load and this sensor showed the high load sensitivity of 10 mN that is higher than human fingers.

Research Progress in the Preparation of Flexible Substrate Barrier Films

2021 ◽  
Vol 1027 ◽  
pp. 91-98
Author(s):  
Li Xia Guan ◽  
Zhao Yi Zhou ◽  
Yi Jing Huang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Flexible Electronics ◽  
Flexible Substrate ◽  
Research Progress ◽  
Barrier Films ◽  
Main Challenge ◽  
Long Life

The development of flexible electronics towards for the direction of bend ability, lightweight, portability, long life against falling. The performance of the substrate in the flexible electronics plays a very important role in the development of electronics. In this article, three preparation technologies of thin films are introduced, including CVD, PVD and ALD. The paper also introduces the research progress on the preparation of substrate barrier films, and one main challenge that may face by the preparation of thin film materials. In order to satisfy the development of flexible electronics, improving the substrate’s performance constantly is needed. Finally, the development of preparing barrier films is prospected.

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