scholarly journals A Hydraulic Soft Microhand with an Application of Live Insect Manipulation

2021 ◽  
Author(s):  
Sina Baghbani Kordmahale ◽  
Jian Qu ◽  
Anastasia Hanifah Muliana ◽  
Jun Kameoka
Keyword(s):  
Pressure Difference ◽  
Soft Material ◽  
Experimental Results ◽  
Circular Membrane ◽  
Casting Technique ◽  
Micro Scale ◽  
Simulation And Experiment ◽  
Membrane Bending ◽  
Center Distance ◽  
Abaqus Software

Abstract We have developed micro scale hydraulic/pneumatic soft grippers and demonstrated the handling of an insect. These grippers are built on Polydimethylsiloxane (PDMS) with the soft material casting technique to form three finger-like columns, which are placed on a circular membrane. The fingers have a length of 1.5mm/2mm and a diameter of 300µm each; the distance between two fingers is 600µm of center-to-center distance. Membrane is built as a 150µm soft skin on the top of a cylindrical void. Applying a pressure difference between the interior of the void and the exterior can bend the membrane. Bending the membrane causes the motion of opening/closing of the gripper, and as a result, the three fingers can grip an object or release it. The PDMS was characterized and the experimental results were used later in Abaqus software to simulate the gripping motion. The produced force and range of deformation of the grippers were investigated by simulation and experiment. The results of the simulation agrees with the experiments. The maximum 543 µN force was measured for the microfluidic compatible microgrippers.Using this microhand gripper, the an ant was manipulated successfully without any damage. Results showed fabricated devices have great potential as a micro/bio manipulator.

scholarly journals Detection of Single Steel Strand Distribution in Grouting Duct Based on Capacitive Sensing Technique

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2564 ◽  
Author(s):  
Nan Li ◽  
Mingchen Cao ◽  
Hangben Du ◽  
Cunfu He ◽  
Bin Wu
Keyword(s):  
Capacitive Sensor ◽  
Experimental Results ◽  
Capacitive Sensing ◽  
Capacitance Measurements ◽  
Position Detection ◽  
Steel Bar ◽  
Sensor Structure ◽  
Steel Strand ◽  
Center Distance ◽  
Post Tensioned

Grouting ducts (containing steel strands) are widely used to increase the structural strengths of infrastructures. The determination of the steel strand’s integrity inside of ducts and the grouting quality are important for a strength evaluation of the structure. In this study, a capacitive sensing technique was applied to identify the cross-sectional distribution of the steel strands. The distribution was expressed in polar coordinates in an external post-tensioned pre-stressed duct model. An improved capacitive sensor structure was designed, which consisted of four electrodes, and different electrode-pairs were used to determine various locations’ information of the steel strands. Two rounds of measurements were conducted using the designed sensor to detect the angle (θ) and center distance (r) of the steel strand in the duct. The simulated and experimental results are presented and analyzed. In general, it is difficult to locate the angle of a steel strand directly from first-round capacitance measurements by analyzing the experimental results. Our method based on Q-factor analysis was presented for the position detection of a steel bar in an external post-tensioned pre-stressed duct. The center distance of the steel bar could be identified by second-round capacitance measurements. The processed results verified the effectiveness of the proposed capacitive sensor structure. Thus, the capacitive sensing technique exhibited potential for steel strand cross-section distribution detection in external post-tensioned pre-stressed ducts.

Design and Analysis of Micro Plastic Heat Exchanger

2012 ◽  
Vol 562-564 ◽  
pp. 1776-1779
Author(s):  
Yue Han ◽  
Heng Zhi Cai ◽  
Ya Jun Zhang ◽  
Da Ming Wu ◽  
Xin Liang Wang
Keyword(s):  
Heat Exchanger ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
Chemical Engineering ◽  
Mechanical Systems ◽  
Experimental Results ◽  
Micro Electro Mechanical Systems ◽  
Micro Heat Exchanger ◽  
Simulation And Experiment ◽  
Energy Engineering

The heat exchanger is widely used in energy engineering, chemical engineering etc. And with development of the MEMS (Micro Electro Mechanical Systems), many researchers are interested in the micro heat exchanger. In this paper, the micro plastic heat exchangers are manufactured by modified PPS. A heat exchanger with polypropylene (PP) is also made for comparison. Simulation and experiment are carried out to determine the thermal performance of the micro plastic heat exchangers. The experimental results are compared with that of simulation. The results show the performance of the micro plastic heat exchanger is very close to that of metal heat exchanger with the same dimension.

Removing Blinks in Video-Oculography

2012 ◽  
Vol 239-240 ◽  
pp. 1165-1168
Author(s):  
Xue Jun Chen ◽  
Chen Hua Zhang
Keyword(s):  
Kalman Filter ◽  
Eye Movement ◽  
Detection Method ◽  
Threshold Level ◽  
Experimental Results ◽  
Video Oculography ◽  
Non Invasive ◽  
Pupil Center ◽  
Simulation And Experiment ◽  
Blink Artifact

Video-oculography (VOG) is a non-invasive detection method used for eye movement. However, during testing, if object blinks, VOG would be difficult to acquire eye movement. A removing blink method based on Kalman Filter was presented. A cubic spline was employed to patch the removed data. Then simulation and experiment were done. The experimental results show that the method well predicts the next state. Compared to a threshold level, it eliminates blink artifact and patches the removed data. The method is a viable means of predicting pupil center for blink in VOG.

scholarly journals Actuation of flexoelectric membranes in viscoelastic fluids with applications to outer hair cells

2014 ◽  
Vol 372 (2029) ◽  
pp. 20130369 ◽  
Author(s):  
E. E. Herrera-Valencia ◽  
Alejandro D. Rey
Keyword(s):  
Hair Cells ◽  
Capillary Flow ◽  
Outer Hair Cells ◽  
Mechanical Power ◽  
Circular Membrane ◽  
Capillary Flows ◽  
Mechanical Power Output ◽  
Membrane Bending ◽  
Circular Capillary ◽  
The Fourier Transform

Liquid crystal flexoelectric actuation uses an imposed electric field to create membrane bending, and it is used by the outer hair cells (OHCs) located in the inner ear, whose role is to amplify sound through generation of mechanical power. Oscillations in the OHC membranes create periodic viscoelastic flows in the contacting fluid media. A key objective of this work on flexoelectric actuation relevant to OHCs is to find the relations and impact of the electromechanical properties of the membrane, the rheological properties of the viscoelastic media, and the frequency response of the generated mechanical power output. The model developed and used in this work is based on the integration of: (i) the flexoelectric membrane shape equation applied to a circular membrane attached to the inner surface of a circular capillary and (ii) the coupled capillary flow of contacting viscoelastic phases, such that the membrane flexoelectric oscillations drive periodic viscoelastic capillary flows, as in OHCs. By applying the Fourier transform formalism to the governing equation, analytical expressions for the transfer function associated with the curvature and electrical field and for the power dissipation of elastic storage energy were found.

Characterization of a Radiantly Driven Multistage Knudsen Compressor

2003 ◽  
Author(s):  
M. Young ◽  
Y. L. Han ◽  
E. P. Muntz ◽  
G. Shiflett
Keyword(s):  
Steady State ◽  
Atmospheric Pressure ◽  
Maximum Flow ◽  
Performance Model ◽  
Experimental Results ◽  
Maximum Pressure ◽  
Flow Rates ◽  
Micro Scale ◽  
Knudsen Compressors

Knudsen Compressors are meso/micro scale gas compressors/pumps based on thermal transpiration or thermal creep. The design of radiantly driven Knudsen Compressors is discussed, along with a model that was developed to understand their performance. Experimental pumping performances for Knudsen Compressors with one, two, five, and fifteen stage, radiantly driven cascades are also discussed. Temperature measurements across the transpiration membranes, for various pressures of Nitrogen, were obtained and compared to those predicted by the performance model. The results agree with the model to within 15% consistently under predicting the measured hot side temperature of the transpiration membrane. The pump-down curves, steady-state maximum pressure differences, and maximum flow rates produced by a single stage Knudsen Compressor were obtained. A variety of configurations were studied at pressures from 500 mTorr to atmospheric pressure. The experimental results agreed with the performance model’s predictions to within 20%.

Shearing and Shaving Process of Stainless Steel Wire at Micro Scale

2020 ◽  
Vol 311 ◽  
pp. 74-79
Author(s):  
Chao Cheng Chang ◽  
Tzu Hsiang Hung ◽  
Jung Shu Chang
Keyword(s):  
Stainless Steel ◽  
Steel Wire ◽  
Load Cell ◽  
Experimental Results ◽  
Stainless Steel Wire ◽  
Displacement Sensor ◽  
Micro Scale ◽  
Steel Wires ◽  
Sheared Edge ◽  
Die Set

This study investigated the effects of the die clearance on the shearing and shaving processes of the stainless steel (SUS316LVM) wire at micro scale. A die set was developed and installed on a precession press equipped with a load cell and a displacement sensor to conduct experiments. By using different punches in the same die set, the specimens prepared from 316LVM stainless steel wires with 0.5 mm diameter were first sheared and then shaved. Experimental results show that the burnished area of the sheared edge increases with the reduction of the clearance between the punch and die in the shearing process. The clearance also significantly affects the load curves. Moreover, the shaving process does increase the burnished area on the shaved edge of the specimen. By an appropriate feed in the shaving process, it is possible to trim the extra material from the sheared edge that results in a nearly complete burnished surface on the shaved edge of the stainless steel wire. This research provides a basis for understanding of the die clearance effect on the shearing and shaving processes at micro scale.

Influence of Cylindrical Inclusion on the Elastic Field of Soft Material Loaded by Wedge Indenter

2014 ◽  
Vol 670-671 ◽  
pp. 664-667
Author(s):  
Xiao Hua Tan ◽  
Wei Qiu ◽  
Xia Xiao
Keyword(s):  
Rigid Inclusion ◽  
Elastic Field ◽  
Contact Stresses ◽  
Soft Material ◽  
Experimental Results ◽  
Cylindrical Inclusion ◽  
Experimental Procedure ◽  
Soft Matrix

In this work, the influence of a rigid cylindrical inclusion on the elastic field in a transparent soft material is studied by an embedded-grating technique. The same experimental procedure was implemented on two specimens, a homogeneous bulk soft material and the same material containing a rigid cylindrical inhomogeneity. Under the indentation of a rigid wedge, two kinds of deformation sectors underneath the contacting boundary are observed from experimental results. Furthermore, the shape of the deformation sectors is horizontally expanded due to the inclusion. A local fluctuation of contact stresses between the soft matrix and rigid inclusion are discussed.

Experimental investigation of pressure distribution between the piston rings and its formation in reciprocating compressors

2012 ◽  
Vol 226 (11) ◽  
pp. 2701-2712 ◽  
Author(s):  
Dianbo Xin ◽  
Jianmei Feng ◽  
Liqing Ding ◽  
Donghui Yang ◽  
Xueyuan Peng
Keyword(s):  
Pressure Distribution ◽  
Pressure Difference ◽  
Piston Ring ◽  
Dynamic Pressure ◽  
Experimental Results ◽  
Suction Pressure ◽  
Piston Rings ◽  
Ring Groove ◽  
Premature Failure ◽  
Contact Position

The severe non-uniformity of pressure distribution has been suggested as the essential reason for the premature failure of piston rings in reciprocating compressors. A test rig was built to investigate the dynamic pressure distribution and its formation process, so that the root cause of the non-uniform pressure distribution could be revealed. The experimental results showed that the pressure distribution between the rings was always significantly non-uniform under various test conditions and the first ring bore more than 75% of the total pressure difference. Further analysis of the experimental data indicated that when the suction pressure was not higher than that in the crank case, the first piston ring switched its contact position with the piston ring groove twice in one cycle, at the angles of around 63° and 170°, respectively, while the others switched contact positions at about 90° and 270°. If the suction pressure was higher than the pressure in the crank case, the first ring still switched its contact position twice in a cycle, at the crank angle of about 47° and 195°, respectively, but the other rings no longer changed their positions. The experimental results also demonstrated that the formation of pressure difference on different rings was not synchronous, which indicated that the rings could not work until their pressure difference reached a critical value.

scholarly journals Preparation and Study of some Electrical Properties of PVA-Ni(NO3)2 Composites

2014 ◽  
Vol 40 ◽  
pp. 36-42 ◽  
Author(s):  
Sabah A. Salman ◽  
Nabeel A. Bakr ◽  
Mohammed H. Mahmood
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
Filler Content ◽  
Experimental Results ◽  
Casting Technique ◽  
Different Temperatures

The aim of this paper is to prepare and study the (D.C.) electrical conductivity of (PVA-Ni (NO3)2) composites at different temperatures. For that purpose, PVA films with Ni (NO3)2 salt additive were prepared with different concentrations‎ 2, 4, 6, 8 and 10 wt. % and with thickness of 45μm by using casting technique. The experimental results for PVA-Ni (NO3)2) ‎films show that the (D.C.) electrical‏ ‏conductivity increased with increasing ‎the filler content and the‏ ‏temperature, and the activation energy was ‎decreased with increasing the filler content‎.

A new cure kinetics model to simulate thermomechanical behavior of polymeric sealants for automotive applications

2021 ◽  
Author(s):  
Jae-Hyuk Choi ◽  
Wonbo Shim ◽  
Chul Hong Rhie ◽  
Woong-Ryeol Yu
Keyword(s):  
Cure Kinetics ◽  
Thermomechanical Behavior ◽  
Experimental Results ◽  
Kinetics Model ◽  
Automotive Applications ◽  
Kinetics Models ◽  
User Material Subroutine ◽  
Simulation Results ◽  
Complex Temperature ◽  
Abaqus Software

Abstract Accurate prediction of the cure level of thermoset polymers is essential to simulate the thermomechanical behavior of polymeric thermoset sealants, which is strongly dependent on cure level. Conventional cure kinetics models, however, fail to accurately predict the cure levels of thermoset sealants subjected to a complex temperature program. Herein, we propose a new cure kinetics model that greatly enhances cure level predictability by considering temperature derivatives. The validity of our model was verified by simulating the thermomechanical behavior of a polymeric sealant using a user material subroutine (UMAT) of ABAQUS software. Experimental results from an appropriately designed thermomechanical test were compared with simulation results obtained from the UMAT.

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