Anisotropic Conducting Film (ACF) of Ag Nanoparticles as Transfer Polymer and Electrical Interface for Silicon Micro- and Nano- Pillars

2011 ◽  
Vol 1303 ◽  
Author(s):  
Matthew Ombaba ◽  
V. J Logeeswaran ◽  
M. Saif Islam
Keyword(s):  
Ag Nanoparticles ◽  
Bottom Electrode ◽  
Electrical Contact ◽  
Lateral Force ◽  
Vertical Force ◽  
Conducting Film ◽  
Conductive Films ◽  
Rubbery State ◽  
Transfer Method ◽  
Anisotropic Conducting

ABSTRACTWe report a novel application of Anisotropic Conductive Films (ACFs) technology to provide electrical contact and mechanical anchor between fracture transfer-printed (1-D) single crystal semiconductor micro- and nanopillars and a bottom metal. This fracture-transfer method enables highly crystalline micro- and nanopillars of different materials with diverse bandgaps and physical properties to be fabricated on appropriate mother substrates and transferred to form multilayered 3D stacks for multifunctional devices. The proposed protocol incorporates silver (Ag) nanoparticles into thermoplastic polymers exploitable in transfer-printed semiconductor devices and circuits with low contact resistance that is compatible with current IC processing methods. The vertical micropillars arrays are then embossed onto the polymer at its rubbery state by applying a vertical force leading to particle trapping between the bottom electrode and the micropillars. The polymer is then hardened while retaining the applied vertical force. By applying a lateral force on the mother substrate, the firmly cemented pillars are fractured off thereby allowing the mother substrate to be reused.

Quantification of Friction Force for Dual-Axis Probe Friction Force Microscope

2009 ◽  
Author(s):  
Hiroaki Amakawa ◽  
Kenji Fukuzawa ◽  
Mitsuhiro Shikida ◽  
Hedong Zhang ◽  
Shitaro Itoh
Keyword(s):  
Friction Force ◽  
Normal Force ◽  
Calibration Method ◽  
Lateral Force ◽  
Vertical Force ◽  
Torsion Beam ◽  
Force Sensitivity ◽  
Mechanical Interference ◽  
Friction Force Microscope ◽  
Mechanical Probe

Conventional friction force microscopes (FFMs) had the disadvantage of low force sensitivity due to mechanical interference between torsion caused by friction force and deflection by normal force. In order to overcome disadvantage, we developed a dual-axis micro-mechanical probe, which measures the lateral force by the double cantilever and the vertical force by the torsion beam. However, the calibration method of the lateral force has not been established. In this study, we present a new calibration method using a step-structure.

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.

Effects of Track Elasticity on Wheel-Rail Dynamic Performance of Heavy Haul Railway

2015 ◽  
Vol 744-746 ◽  
pp. 1249-1252 ◽  
Author(s):  
Yong Zeng
Keyword(s):  
Lateral Displacement ◽  
Dynamic Performance ◽  
Lateral Force ◽  
Vertical Force ◽  
Heavy Vehicles ◽  
Derailment Coefficient ◽  
Heavy Haul ◽  
Dynamics Models ◽  
Heavy Haul Railway ◽  
The Impact

Two vehicle-track dynamics models on heavy haul railway are established in two conditions of rigid track and elastic track. And the impact of track elasticity on the wheel-rail dynamics performance was analyzed using models. The results show that the critical speed of heavy vehicles and wheel-rail dynamic indexes, such as wheel-rail lateral force and wheel-rail vertical force decreased on elastic track compared with rigid track. However, other dynamic indexes, including derailment coefficient and lateral displacement of wheelsets increased on elastic track. And the wheel-rail wear indexes are some differences on two tracks.

scholarly journals Is Anterior Guidance a Key Factor on Planning Implant Treatment for Free-End Missing in the Posterior Mandible?

2019 ◽  
Vol 45 (2) ◽  
pp. 100-105 ◽  
Author(s):  
Mitsuharu Nagao ◽  
Chihiro Masaki ◽  
Mihoko Nakao ◽  
Yoshinori Ito ◽  
Shintaro Tsuka ◽  
...  
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Lateral Force ◽  
Von Mises Stress ◽  
Vertical Force ◽  
Experimental Conditions ◽  
Element Analysis ◽  
Implant Placement ◽  
Ct Data ◽  
Implant Treatment

To perform safe implant treatment, the anatomical structure and bone quality at implant placement sites are evaluated based on a patient's computerized tomography (CT) data, but there is no definite method to determine placement sites and the appropriate number of implants. The objective of this study was to investigate the influence of the number and arrangement of implants on the stress distribution in 3-unit posterior fixed partial dentures for the posterior mandible by mechanical analysis using the finite element method. Three-dimensional finite element analysis models were constructed from the CT data of a patient with missing mandibular teeth (Nos. 35, 36, 37). Implant placement was simulated under various conditions. Superstructures were connected and fixed with a titanium frame. As the loading conditions, 400 N vertical and lateral loads (45° on the lingual side and 45° on the buccal side) were applied to the upper areas of Nos. 35, 36, and 37, and the stress distribution and frame displacement were evaluated. When a vertical force was applied, no difference of the von Mises stress was noted among the 5 experimental conditions. When lateral force was applied from the lingual and buccal sides at 45°, the stress was higher than that induced by vertical force under all conditions, and it was especially high under mesial and distal cantilever conditions. When displacement of the titanium frame was measured, the displacement caused by lateral force was greater than that due to vertical force. In addition, comparison between long and short distal cantilever bridges revealed that displacement of the titanium frame tended to be smaller when the short cantilever was used. These findings suggested that the stress on peri-implant tissues and displacement of the titanium frame vary depending on the configuration and number of implants, with greater stress and more marked displacement of the titanium frame being induced by lateral force when the number of implants is reduced and a cantilever bridge is selected.

Force Exertion during Lifting with Light Loads

1974 ◽  
Vol 18 (4) ◽  
pp. 393-396
Author(s):  
Ronald Perkins ◽  
Stephan Konz
Keyword(s):  
Male Subject ◽  
Peak Stress ◽  
Lateral Force ◽  
The Body ◽  
Vertical Force ◽  
Final Position ◽  
Single Male ◽  
Object Weight ◽  
Before And After ◽  
Body Center

A single male subject lifted a tote box 12 times at each of 24 conditions while standing on a force platform. The 24 conditions were 6 combinations of initial and final position (floor to 12,24 and 36 in. shelf, floor plus 12 in. to 24 and 36 in. shelf, and floor plus 24 in. to 36 in. shelf) x 2 box weights (11 and 22 lbs.) and 2 distances of the box from the body center of gravity (16 and 20 in.). Averaged over all 24 conditions, peak vertical force was 46 lbs., frontal force was 6 lbs., lateral force was 2 lbs., somersault torque was 417 in.-lbs., cartwheel torque was 75 in.-lbs., twist torque was 59 in.-lbs. and peak box acceleration was .3 g. For lifting with light loads, object weight has much less effect on stress than might be expected. Peak forces occurred in the .5 sec. before and after grasping the box. In fact, peak stress occurred before the box was grasped in 66% of the lifts.

Ferroelectric Properties of Pb(Zr,Ti)O3 Thin Film Capacitors Made by RF Magnetron Sputtering and Heat-Treated by the Bottom Electrode Crystallization Method

2006 ◽  
Vol 514-516 ◽  
pp. 1348-1352
Author(s):  
Andréi I. Mardare ◽  
Cezarina C. Mardare ◽  
Raluca Savu
Keyword(s):  
Thin Film ◽  
Magnetron Sputtering ◽  
Bottom Electrode ◽  
Ferroelectric Properties ◽  
Electrical Contact ◽  
Rf Magnetron Sputtering ◽  
Electrical Contacts ◽  
Sem Images ◽  
Heat Treated ◽  
Pzt Films

The bottom electrode crystallization (BEC) method was applied to the crystallization of Pb(Zr,Ti)O3 (PZT) thin films deposited by RF magnetron sputtering on Pt/Ti/SiO2/Si substrates. Using a proportional-integral-differential controller, the current flowing in the Pt/Ti films provided accurately controlled Joule heating for the crystallization of the PZT films. The temperature uniformity of the heat treatments was investigated by measuring the ferroelectric properties of PZT. Platinum and tungsten wires were alternatively used as electrical contacts. Scanning electron microscopy (SEM) images were used to inspect the electrical contact regions between the platinum films and different contact wires. The PZT films showed higher remanent polarizations and lower leakage currents near the electrical contacts when Pt wires were used; the ferroelectric properties were more uniform on the PZT films heat-treated with W contact wires. The BEC method can successfully replace the more conventional means for thin film crystallization, having the advantage of being a very precise, low cost and low power consumption technique.

Electrical Contact Characteristics between Silicon Micropillars and Ag Nanoparticles with Controlled Mechanical Load

2012 ◽  
Vol 1429 ◽  
Author(s):  
VJ Logeeswaran ◽  
Mark Triplett ◽  
Daniel Lam ◽  
Emre Yengel ◽  
Heim Grewal ◽  
...  
Keyword(s):  
Ag Nanoparticles ◽  
High Performance ◽  
Mechanical Load ◽  
Electrical Contact ◽  
Test Method ◽  
Transfer Printing ◽  
Glass Substrates ◽  
Current Voltage ◽  
Force Resolution ◽  
Nano Wires

ABSTRACTWe report an experimental investigation on employing Ag nanoparticles to provide electrical and mechanical contacts between transfer-printed semiconductor devices in the shape of micro/nano- wires and pillars. The Ag nanoparticles have diameters ranging between 200-800nm and are assembled on a 200nm Au film deposited on glass substrates. With a customized tool, an ensemble of silicon pillars were brought into contact with the silver (Ag) nanoparticles (AgNPs) by precisely controlling the displacement and applied force (pressure). Current-voltage measurements were done at force resolution of ~0.2N. The test method aims to illuminate the pillar-particle contact mechanism using the nanoparticles as conductive fillers for the next generation of high performance heteroepitaxial device transfer-printing applications.

Interfacing Ag Nanoparticles with 1D Semiconductor Micro/Nanostructures via Joule Heating for Transfer Printing Nanodevices at Room Ambient

2012 ◽  
Vol 1429 ◽  
Author(s):  
VJ Logeeswaran ◽  
Aaron M. Katzenmeyer ◽  
Mark Triplett ◽  
Matthew Ombaba ◽  
M. Saif Islam
Keyword(s):  
Joule Heating ◽  
Ag Nanoparticles ◽  
Ohmic Contacts ◽  
Electrical Contact ◽  
Electrical Current ◽  
Transfer Printing ◽  
Ambient Conditions ◽  
Particle Deformation ◽  
Au Film ◽  
Self Assembled

ABSTRACTWe describe an experiment to interface and characterize silver nanoparticle (AgNPs) aggregates that are self-assembled and plastically deformable on a thin gold (Au) film deposited on glass substrate. The electrical characterization is done using an electrical nanoprobe attached to a nano-manipulator inside a scanning electron microscope (SEM). Electrical current-voltage (I-V) measurements are made between the electrical nanoprobe in contact with the nanoparticle and the Au film. The Ag nanoparticles have diameters ranging between ~200-800nm and are self-assembled on a thiolated 100nm Au film. Application of a contact force via the nanoprobe even after substantial particle deformation reveals initially a small non-linear current. Upon current annealing through Joule heating, significant improvement in the electrical contact at the AgNP/substrate interface was observed. This is most likely based on bonding of the AgNPs to the Au film after passage of a high current. The need for such an annealing/sintering step will be critical in forming good ohmic contacts at ambient conditions during transfer printing of semiconductor micro/nanopillars.

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