Force Response of Single Living Cells Due to Localized Deformation (Invited Talk)

2002 ◽  
Author(s):  
T. Saif ◽  
C. Sager ◽  
S. Coyer
Keyword(s):  
Mechanical Response ◽  
Single Crystal Silicon ◽  
Fibroblast Cell ◽  
Force Sensor ◽  
Local Deformation ◽  
Force Response ◽  
Localized Deformation ◽  
Crystal Silicon ◽  
Micro Electro Mechanical Systems ◽  
Adhesion Site

We present a method for measuring the mechanical response of a single cell in-situ when local deformation is applied at an adhesion site(s) by a functionalized MEMS (Micro Electro Mechanical Systems) force sensor with pN – nN force resolution, and with force and displacement ranges of 100s of nNs and μms. The force sensor is a micro mechanical cantilever beam made of single crystal silicon (SCS), coated by a thin layer of Fibronectin, an extra cellular matrix (ECM) protein, to activate cell adhesion. The end of the beam is brought in contact with a cell to form the adhesion site(s). The cantilever is then moved away from the cell to locally deform it. The force on the cell is measured from the deformation of the cantilever until the adhesion sites fails. We demonstrate the method by deforming several endothelial and fibroblast cells. Force response of the fibroblast cell shows linear behavior.

Micro-Patterning of Silicon by Frictional Interaction and Chemical Reaction

1998 ◽  
Vol 120 (2) ◽  
pp. 353-357 ◽  
Author(s):  
Dae-Eun Kim ◽  
Jae-Joon Yi
Keyword(s):  
Chemical Reaction ◽  
Low Cost ◽  
Three Dimensional ◽  
Single Crystal Silicon ◽  
Crystal Silicon ◽  
Micro Electro Mechanical Systems ◽  
Micro Patterning ◽  
Frictional Interaction ◽  
Micro Structures ◽  
Micro Patterns

In this paper a novel and economical method of generating three-dimensional micro-patterns on single crystal silicon without the need for a mask is presented. The technique is based on the fundamental understanding of frictional interaction at light loads. Micro-patterning is done through a two-step process that comprises mechanical scribing and chemical etching. The basic idea is to induce micro-plastic deformation along a prescribed track through frictional interaction between the tool and the workpiece. Then, by exposing the surface to a chemical under controlled conditions, preferential chemical reaction is induced along the track to form hillocks about 5 μm wide and 1 μm high. This method of micro-machining may be used for making patterns in micro-electro-mechanical systems (MEMS) at low cost. Furthermore, this process demonstrates how microtribological processes can be utilized in the fabrication of micro-structures.

scholarly journals A Constitutive Model for the Mechanical Behavior of Single Crystal Silicon at Elevated Temperature

2001 ◽  
Vol 687 ◽  
Author(s):  
H.-S. Moon ◽  
L. Anand ◽  
S. M. Spearing
Keyword(s):  
High Temperature ◽  
Constitutive Model ◽  
Single Crystal ◽  
Mechanical Behavior ◽  
Elevated Temperatures ◽  
Single Crystal Silicon ◽  
Operational Environment ◽  
Localized Deformation ◽  
Creep Tests ◽  
Crystal Silicon

AbstractSilicon in single crystal form has been the material of choice for the first demonstration of the MIT microengine project. However, because it has a relatively low melting temperature, silicon is not an ideal material for the intended operational environment of high temperature and stress. In addition, preliminary work indicates that single crystal silicon has a tendency to undergo localized deformation by slip band formation. Thus it is critical to obtain a better understanding of the mechanical behavior of this material at elevated temperatures in order to properly exploit its capabilities as a structural material. Creep tests in simple compression with n-type single crystal silicon, with low initial dislocation density, were conducted over a temperature range of 900 K to 1200 K and a stress range of 10 MPa to 120 MPa. The compression specimens were machined such that the multi-slip <100> or <111> orientations were coincident with the compression axis. The creep tests reveal that response can be delineated into two broad regimes: (a) in the first regime rapid dislocation multiplication is responsible for accelerating creep rates, and (b) in the second regime an increasing resistance to dislocation motion is responsible for the decelerating creep rates, as is typically observed for creep in metals. An isotropic elasto-viscoplastic constitutive model that accounts for these two mechanisms has been developed in support of the design of the high temperature turbine structure of the MIT microengine.

Multiple Wafer Bonding for MEMS Applications

2001 ◽  
Vol 681 ◽  
Author(s):  
M. Reiche ◽  
M. Haueis ◽  
J. Dual ◽  
C. Cavalloni ◽  
R. Buser
Keyword(s):  
Wafer Bonding ◽  
Microelectromechanical Systems ◽  
Single Crystal Silicon ◽  
Force Sensor ◽  
Semiconductor Wafer ◽  
Crystal Silicon ◽  
Static Loads ◽  
3 Dimensional ◽  
Wafer Direct Bonding ◽  
Better Than

ABSTRACTMost of the microelectromechanical systems (MEMS) require a 3-dimensional architecture which can efficiently be realized by multiple semiconductor wafer direct bonding. The present paper demonstrates the method on a force sensor for high resolution measurements of static loads. To minimize temperature stress an all-in silicon solution was developed in contrast to micromachined resonant force sensors published already in the literature.The presented force sensor integrates load coupling, the excitation and detection of the vibration of the microresonator in one and the same single crystal silicon package. First measurements proved a sensitivity of 26 Hz/N and a resolution better than 3 mN.

Fabrication Comparison of the SCS-Based and SOI-Based Micromachining

2014 ◽  
Vol 926-930 ◽  
pp. 881-884
Author(s):  
Qing Hua Chen ◽  
Yan Mei Li ◽  
Ying Jun Chen ◽  
Wen Gang Wu
Keyword(s):  
Single Crystal ◽  
Mechanical Systems ◽  
Single Crystal Silicon ◽  
Stress Factor ◽  
Silicon On Insulator ◽  
Device Layer ◽  
Crystal Silicon ◽  
Micro Electro Mechanical Systems ◽  
Polysilicon Layer

The two different fabrications of the Micro-Electro-Mechanical Systems (MEMS) mirrors were compared: a single-crystal-silicon (SCS)-based micromachining and a silicon-on-insulator (SOI)- based micromachining. While the SOI parts had significantly smaller curved device appearance, they were outperformed in most areas by the SCS parts. This was due primarily to the smaller stress factor in the device layer in the SOI parts compared to the polysilicon layer used in the SCS parts.

Probe-Type Microforce Sensor for Mirco/Nano Experimental Mechanics

2008 ◽  
Vol 33-37 ◽  
pp. 943-948 ◽  
Author(s):  
Xi De Li ◽  
Zhao Zhang
Keyword(s):  
Single Crystal Silicon ◽  
Force Sensor ◽  
Radius Of Curvature ◽  
Probe Type ◽  
Crystal Silicon ◽  
Atomic Force ◽  
Highly Sensitive ◽  
Small Force ◽  
Force Resolution ◽  
P Type

In recent years with the development of MEMS and NEMS, various micro and nano scale experiments are required. In general, the smaller the sample, the smaller the force is in the measurement. But it is difficult to load and measure such small force. We developed a probe-type loading and force sensor system to measure micro/nano samples. The system employs a semiconductor strain gauge of a cantilever type sensor and a micro manipulator. A highly sensitive, stable sensing cantilever beam made of single crystal silicon is ion implanted to form the P-type resistor (strain sensor). A tungsten probe with 100 nm radius of curvature was attached to the end of the cantilever as the micro loading tip. We constructed the measurement system and investigated its properties, such as linearity, dynamic response and stability. We also employed microspeckle interferometry to calibrate the force sensor. In preliminary experiments, we successfully obtained the force resolution 0.7 μN and applied our probe-type microforce sensor to calibrate an atomic force microscope (AFM) probe beam and test a single silkworm filament.

HREM observation of dislocations near room temperature fractures in silicon

1988 ◽  
Vol 46 ◽  
pp. 892-893
Author(s):  
M. H. Rhee ◽  
W. A. Coghlan
Keyword(s):  
Cross Section ◽  
Room Temperature ◽  
Single Crystal Silicon ◽  
Dislocation Nucleation ◽  
Back Side ◽  
Ion Milling ◽  
Crystal Silicon ◽  
Flat Surfaces ◽  
Induced Fractures ◽  
Vicker’S Microhardness

Silicon is believed to be an almost perfectly brittle material with cleavage occurring on {111} planes. In such a material at room temperature cleavage is expected to occur prior to any dislocation nucleation. This behavior suggests that cleavage fracture may be used to produce usable flat surfaces. Attempts to show this have failed. Such fractures produced in semiconductor silicon tend to occur on planes of variable orientation resulting in surfaces with a poor surface finish. In order to learn more about the mechanisms involved in fracture of silicon we began a HREM study of hardness indent induced fractures in thin samples of oxidized silicon.Samples of single crystal silicon were oxidized in air for 100 hours at 1000°C. Two pieces of this material were glued together and 500 μm thick cross-section samples were cut from the combined piece. The cross-section samples were indented using a Vicker's microhardness tester to produce cracks. The cracks in the samples were preserved by thinning from the back side using a combination of mechanical grinding and ion milling.

Analysis of Silicon-On-Insulator Structures Formed By Oxygen Ion Implantation

1985 ◽  
Vol 43 ◽  
pp. 300-301
Author(s):  
N. Lewis ◽  
E. L. Hall ◽  
A. Mogro-Campero ◽  
R. P. Love
Keyword(s):  
Ion Implantation ◽  
Single Crystal ◽  
Single Crystal Silicon ◽  
Silicon Layer ◽  
Device Fabrication ◽  
Silicon On Insulator ◽  
High Dose ◽  
Crystal Silicon ◽  
Oxygen Ion ◽  
Oxygen Ion Implantation

The formation of buried oxide structures in single crystal silicon by high-dose oxygen ion implantation has received considerable attention recently for applications in advanced electronic device fabrication. This process is performed in a vacuum, and under the proper implantation conditions results in a silicon-on-insulator (SOI) structure with a top single crystal silicon layer on an amorphous silicon dioxide layer. The top Si layer has the same orientation as the silicon substrate. The quality of the outermost portion of the Si top layer is important in device fabrication since it either can be used directly to build devices, or epitaxial Si may be grown on this layer. Therefore, careful characterization of the results of the ion implantation process is essential.

Strain measurement by means of bend contour microscopy

1989 ◽  
Vol 47 ◽  
pp. 210-211
Author(s):  
Philip D. Hren
Keyword(s):  
Strain Measurement ◽  
Large Angle ◽  
Single Crystal Silicon ◽  
Convergent Beam Electron Diffraction ◽  
Zone Axis ◽  
Silicon Membrane ◽  
Crystal Silicon ◽  
Contour Pattern ◽  
Convergent Beam ◽  
Low Symmetry

The pattern of bend contours which appear in the TEM image of a bent or curled sample indicates the shape into which the specimen is bent. Several authors have characterized the shape of their bent foils by this method, most recently I. Bolotov, as well as G. Möllenstedt and O. Rang in the early 1950’s. However, the samples they considered were viewed at orientations away from a zone axis, or at zone axes of low symmetry, so that dynamical interactions between the bend contours did not occur. Their calculations were thus based on purely geometric arguments. In this paper bend contours are used to measure deflections of a single-crystal silicon membrane at the (111) zone axis, where there are strong dynamical effects. Features in the bend contour pattern are identified and associated with a particular angle of bending of the membrane by reference to large-angle convergent-beam electron diffraction (LACBED) patterns.

TEM characterization of Au/Polysilicon interactions

1990 ◽  
Vol 48 (4) ◽  
pp. 650-651
Author(s):  
N. David Theodore ◽  
Leslie H. Allen ◽  
C. Barry Carter ◽  
James W. Mayer
Keyword(s):  
Solid Phase ◽  
Single Crystal Silicon ◽  
Chemical Vapor ◽  
Electrical Contacts ◽  
Silicon Substrates ◽  
Crystal Silicon ◽  
Transmission Electron ◽  
Polysilicon Films ◽  
The Stability

Metal/polysilicon investigations contribute to an understanding of issues relevant to the stability of electrical contacts in semiconductor devices. These investigations also contribute to an understanding of Si lateral solid-phase epitactic growth. Metals such as Au, Al and Ag form eutectics with Si. reactions in these metal/polysilicon systems lead to the formation of large-grain silicon. Of these systems, the Al/polysilicon system has been most extensively studied. In this study, the behavior upon thermal annealing of Au/polysilicon bilayers is investigated using cross-section transmission electron microscopy (XTEM). The unique feature of this system is that silicon grain-growth occurs at particularly low temperatures ∽300°C).Gold/polysilicon bilayers were fabricated on thermally oxidized single-crystal silicon substrates. Lowpressure chemical vapor deposition (LPCVD) at 620°C was used to obtain 100 to 400 nm polysilicon films. The surface of the polysilicon was cleaned with a buffered hydrofluoric acid solution. Gold was then thermally evaporated onto the samples.

Sign in / Sign up

Export Citation Format

Share Document