Massachusetts Institute of Technology

California Institute of Technology

Other

Nanyang Technological University

Brown University

Inventium LLC

Subra Suresh

Antonios E Giannakopoulos

Ares J Rosakis

Antonios Giannakopoulos

Ming Dao

Jorge Alcala

Scott R Manalis

Ju Li

Thomas P Burg

Zhe Shi

Nitin P Padture

Ilan Blech

Ole Jorgensen

George E Karniadakis

Ken Babcock

Rajendran Thampuran

Marten Olsson

Tae-Soon Park

Marc Finot

Olivera Kesler

Lu Lu

Juthamas Jitcharoen

Methods and apparatus for extracting one or more mechanical properties for a material based on one or more indentation parameters for the material. The method comprises receiving load-displacement data from one or more instrumented indentation tests on the material, determining, by at least one computer processor, the indentation parameters for the material based, at least in part, on the received load-displacement data, providing as input to a trained neural network, the indentation parameters for the material, determining, based on an output of the trained neural network, the one or more mechanical properties of the material, and displaying an indication of the determined one or more mechanical properties of the material to a user of the computer system.

Machine learning techniques for estimating mechanical properties of materials

Compositions and methods related to straining defect doped materials as well as their methods of use in electrical circuits are generally described.

Elastic strain engineering of defect doped materials

The method and apparatus of the present invention detects changes in cell biomechanics caused by any of a variety of diseases and conditions. In one embodiment, the method and apparatus of the invention detect infection of red blood cells. In one embodiment, the invention is a method and apparatus comprising a microfluidic channel with a constriction, for trapping infected red blood cells while allowing healthy red blood cells to deform and pass through the channel. In another embodiment, the invention comprises a suspended microchannel resonator for detecting and counting red blood cells at the constriction of the microfluidic channel.

Method and apparatus for high throughput diagnosis of diseased cells with microchannel devices

Methods and systems for evaluating stresses in line features formed on substrates. Stresses may be computed from measured curvature information based on simple analytical functions. The curvature information can be obtained optically by, e.g., a coherent gradient sensing method, to obtain a full-field measurement of an illuminated area.

Systems for measuring stresses in line features formed on substrates

Techniques for determining large deformation of layered or graded structures to include effects of body forces such as gravity, electrostatic or electromagnetic forces, and other forces that uniformly distribute over the structures, support forces, and concentrated forces. A real-time stress monitoring system is also disclosed to provide in-situ monitoring of a device based on the large deformation analytical approach. A coherent gradient sensing module, for example, may be included in such a system.

Determining large deformations and stresses of layered and graded structures to include effects of body forces

An article is provided that is highly resistant to localized normal indentation, or indentation tensile stresses, against its surface. The article is a stacked array of at least five layer units each having local anisotropy in at least one direction. Each unit has an adjacent unit that differs in a mechanical property, or offset in principle axis of anisotropy by less than 45&deg;. The article forms part of a construction constructed and positioned to withstand indentation, or contact damage, detrimental to its use having a component normal to any tangent of the surface. The article can be a stacked array of fiber-reinforced polymeric material, i.e., prepreg, with the fiber direction offset from each layer to the next by less than 45&deg;. Methods of making the article and methods of use of the article to resist impact are provided. Also provided are articles having surfaces, the surfaces being constructed and arranged to withstand sliding contact stress. The surfaces of these articles are functionally-graded.

Functionally-graded materials and the engineering of tribological resistance at surfaces

Real-time evaluation of stress fields and properties in line features formed on substrates

Techniques for evaluating curvatures in line features embedded in a different material layer formed on a substrate. A model based a uniform layer formed over a substrate may be used to represent a structure with parallel line features embedded in a layer formed over the substrate. The curvatures of the uniform layer due to an elastic distortion along a first direction substantially parallel to the line features and along a second direction orthogonal to the first direction are determined. Next, the curvatures of the uniform layer may be used as respective curvatures of each of the line features.

Technique for determining curvatures of embedded line features on substrates

Provided are methods and apparatus for determining from indentation testing the preexisting stress and/or effective strain in a section of a material. The invention also provides methods and apparatus for determining the variation of the stress with depth in the material (e.g. the gradient). According to the invention, first data are provided from an indentation test of the stressed (or strained) section. The stress (or effective strain) can then be determined from the first data and from second data characteristic of the material, such as a stress-strain curve. Second data can also be obtained from an additional indentation test of a section having a known stress. The methods provided herein are suitable for programming on a general purpose computer or calculator.

Method and apparatus for determining preexisting stresses based on indentation or other mechanical probing of the material

Depth sensing indentation and methodology for mechanical property measurements

Method and apparatus for determining preexisting stresses based on

An indentation measurement apparatus is retrofittable onto any of a variety of load-applying frames and includes a mount for mounting an indenter of any geometry (for example blunt or sharp). The arrangement is very stiff and mechanical values including Young's modulus, strain hardening exponent, yield strength, and hardness can be obtained from a single load/unload versus displacement test. A wide variety of materials can be tested using the apparatus. An optical probe can measure displacement of the indenter head relative to a sample. A new method of calculating strain hardening directly from load/displacement measurement is presented as is a new method of calculating strain hardening exponent.

Depth sensing indentation and methodology for mechanical property

Techniques for the determination of mechanical properties of homogenous or functionally-graded materials from indentation testing are presented. The technique is applicable to indentation on the nano-scale through the macro-scale including the geological scale. The technique involves creating a predictive load/depth relationship for a sample, providing an experimental load/depth relationship, comparing the experimental data to the predictive data, and determining a physical characteristic from the comparison.

Method and apparatus for determination of mechanical properties of

A technique for determining properties such as Young's modulus, coefficient of thermal expansion, and residual stress of individual layers within a multi-layered sample is presented. The technique involves preparation of a series of samples, each including one additional layer relative to the preceding sample. By comparison of each sample to a preceding sample, properties of the topmost layer can be determined, and residual stress at any depth in each sample, resulting from deposition of the top layer, can be determined.

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Wellesley, MA, United States of America

Subra Suresh