- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Laser-Assisted Fabrication of a Highly Sensitive and Flexible Micro Pyramid-Structured Pressure Sensor for E-Skin Applications
摘要： A novel capacitive pressure sensor based on micro-structured polydimethylsiloxane (PDMS) dielectric layer was developed for wearable E-skin and touch sensing applications. The pressure sensor was fabricated on a flexible polyethylene terephthalate (PET) substrate, using PDMS and silver (Ag) as the dielectric and electrode layers, respectively. A set of PDMS films with pyramid shaped micro-structures were fabricated using a laser engraved acrylic mold. The electrodes (top and bottom) were fabricated by depositing Ag on PET films using additive screen-printing process. The pressure sensor was assembled by attaching the top and bottom Ag electrodes to the smooth side of pyramid shaped micro-structured PDMS (PM-PDMS) films. The top PM-PDMS was then placed on the bottom PM-PDMS. The capability of the fabricated pressure sensor was investigated by subjecting the sensor to pressures ranging from 0 to 10 kPa. A sensitivity of 0.221% Pa-1, 0.033% Pa-1 and 0.011% Pa-1 along with a correlation coefficient of 0.9536, 0.9586 and 0.9826 was obtained for the pressure sensor in the pressure range of 0 Pa to 100 Pa, 100 Pa to 1000 Pa, and 1 kPa to 10 kPa, respectively. The pressure sensor also possesses a fast response time of 50 ms, low hysteresis of 0.7%, recovery time of 150 ms and excellent cycling stability over 1000 cycles. The results demonstrated the efficient detection of pressure generated from various activities such as hand gesture and carotid pulse measurement. The PM-PDMS based pressure sensor offers a simple and cost-effective approach to monitor pressure in E-skin applications.
关键词： E-skin,Laser patterning,Pressure sensor,Micro-pyramid structure,Polydimethylsiloxane (PDMS),Screen printing process,Polyethylene terephthalate (PET)
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE International Conference on Sensors and Nanotechnology (SENSORS & NANO) - Penang, Malaysia (2019.7.24-2019.7.25)] 2019 IEEE International Conference on Sensors and Nanotechnology - Optimization of CO <sub/>2</sub> Laser Power for Patterning of Single-layer Graphene for Advanced Devices Applications
摘要： Transparent conductive films (TCFs) made of graphene and its composite materials have emerged as potential electrodes for advanced devices such as sensors, light emitting diodes (LEDs), organic LEDs, solar cells and supercapacitors. The TCFs need to be patterned to make their use in these devices. In this work, the patterning of such TCF is carried out by CO2 laser. Different laser power levels are optimized for effective patterning of single-layer graphene film transferred to the transparent substrates such as microscopic glass slides and polyethylene terephthalate (PET). Moreover, the effect of different laser power levels on the electrical property of graphene TCFs before and after patterning is also examined. It is found that the patterned graphene TCFs are free from film narrowing, wrapping, and bundle formation at different power levels. It is also found that the sheet resistance of patterned graphene film remains the same after CO2 laser-based ablation process. The optimized conditions of CO2 laser-based patterning offer a facile, fast, and time-saving technique to pattern the single layer graphene.
关键词： laser,patterning,thin film,graphene,TCF
更新于2025-09-16 10:30:52
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Morphologically modulated laser-patterned reduced graphene oxide strain sensors for human fatigue recognition
摘要： Laser heating provides an effective method to produce thermally reduced graphene oxide (rGO), it can also pattern the designed layout on the surface of graphene oxide (GO) during the reduction process. In this work, we demonstrated a flexible strain sensor based on the morphologically modulated laser-patterned reduced graphene oxide (LPG) film with a one-step process. Compared with the strain sensor using flat patterned rGO (0-1.2%) and curved-grid patterned rGO (CGPG) (0-4.1%), the strain sensor based on rectangular-grid patterned rGO (RGPG) have highest gauge factor (GF), up to 133 under 2.7% of physical deformation. Meanwhile, the RGPG strain sensors exhibit extraordinary linearity in a relatively large range of deformation (0-2.7%) and excellent endurance for over 1000 stretching-releasing circles. The RGPG strain sensor was used to monitor human fatigue. By analyzing eye blinking frequency and duration, it is possible to evaluate the fatigue level. We anticipate that the RGPG based strain sensor, prepared via a relatively simple and cost-effective process, may open up a broad spectrum of practical applications, such as driver fatigue evaluation and smart monitoring of human body movements.
关键词： wearable electronics,laser patterning,fatigue evaluation,flexible strain sensor,reduced graphene oxide
更新于2025-09-12 10:27:22
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Direct Laser Patterning and Phase Transformation of 2D PdSe <sub/>2</sub> Films for On-Demand Device Fabrication
摘要： Heterophase homojunction formation in atomically thin 2D layers is of great importance for next-generation nanoelectronics and optoelectronics applications. Technologically challenging, controllable transformation between the semiconducting and metallic phases of transition metal chalcogenides is of particular importance. Here, we demonstrate that controlled laser irradiation can be used to directly ablate PdSe2 thin films using high power or trigger the local transformation of PdSe2 into a metallic phase PdSe2?x using lower laser power. Such transformations are possible due to the low decomposition temperature of PdSe2 and a variety of stable phases compared to other 2D transition metal dichalcogenides. Scanning transmission electron microscopy is used to reveal the laser-induced Se-deficient phases of PdSe2 material. The process sensitivity to the laser power allows patterning flexibility for resist-free device fabrication. The laser-patterned devices demonstrate that a laser-induced metallic phase PdSe2?x is stable with increased conductivity by a factor of about 20 compared to PdSe2. These findings contribute to the development of nanoscale devices with homojunctions and scalable methods to achieve structural transformations in 2D materials.
关键词： device fabrication,phase transformation,PdSe2,FET,laser patterning,2D materials,graphene
更新于2025-09-12 10:27:22
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A resist-less patterning method of Al thin film on polycarbonate by F2 laser irradiation
摘要： In recent years, polycarbonate is gathering interests as light and strong material for smart windows. In this paper, a resist-less patterning method of Al thin ?lm on silicone hard-coated polycarbonate by 157 nm F2 laser irradiation is reported. A photomask placed on Al thin ?lm on polycarbonate and irradiated with F2 laser and the non-irradiated area was removed by KOH aq. The mechanism of the method was examined by XPS measurement and it represents that the surface of Al thin ?lm is modi?ed to Al2O3 by F2 laser irradiation and the Al2O3 surface prevents the chemical etching. The ATR-FTIR and XPS measurements of polycarbonate surface under Al thin ?lm imply that the silicone hard coat layer of polycarbonate was oxidized by F2 laser irradiation even under Al thin ?lm and Al-O-Si bonds might be formed between Al and silicone hard coat interface. The formation of Al2O3 at the surface of Al thin ?lm and Al-O-Si bonds at Al/silicone hard coat interface are expected to give abrasion resistance and strong adhesion for Al thin ?lm on silicone hard-coated polycarbonate. This patterned Al ?lm fabrication method contributes to the manufacturing of electrodes for smart polycarbonate windows.
关键词： Surface modi?cation,Metal thin ?lm,VUV laser,Patterning,Chemical etching
更新于2025-09-12 10:27:22