Harvard College

Yeda Research and Develpment & Co. Ltd

Nano Terra Inc.

Adam Winkleman

George M Whitesides

Raquel Perez-Castillejos

Ron Naaman

Katherine Andrea Mirica

Jeffrey D Carbeck

Sergey S Shevkoplyas

Dan Oron

Andres W Martinez

Sandip Agarwal

Scott T Phillips

Qiaobing Xu

Emanuel Carrilho

Michal Lahav

Brian T Mayers

Max Narovlyansky

Malancha Gupta

Phillip W Snyder

Katherine L Gudiksen

Emily A Weiss

Leonard N J Rodriguez

David Ledoux

Kevin Randall Stewart

Tingbing Cao

Ben Golan

Zeev Fradkin

The ability to levitate, to separate, and to detect changes in density using diamagnetic particles suspended in solutions containing paramagnetic cations using an inhomogeneous magnetic field is described. The major advantages of this separation device are that: i) it is a simple apparatus that does not require electric power (a set of permanent magnets and gravity are sufficient for the diamagnetic separation and collection system to work); ii) it is compatible with simple optical detection (provided that transparent materials are used to fabricate the containers/channels where separation occurs; iii) it is simple to collect the separated particles for further processing; iv) it does not require magnetic labeling of the particles/materials; and v) it is small, portable. The method and kits provided provide for separation and collection of materials of different densities, diagnostics for detection of analytes of interest, monitoring of solid-supported chemical reactions and determination of densities of solid and liquid mixtures.

Density-based methods for separation of materials, monitoring of solid supported reactions and measuring densities of small liquid volumes and solids

In one aspect, methods of patterning of thin films of an ionotropic polymer (e.g., poly(acrylic acid)) are provided. These processes can create micron or sub-micron-scale patterns of ionotropic polymers such as cation crosslinked poly(acrylic acid) (CCL-PAA). In one embodiment, patterning may be performed within microfluidic channels by flowing a solution of crosslinking agent (e.g., metal cations such as Ag, Ca, Pd, Al, La, and Ti) that can crosslink a portion of an ionotropic polymer in contact with the solution. In another embodiment, methods of patterning ionotropic polymers involve photolithography. Upon patterning a positive photoresist (e.g., diazonaphthoquinone-novolac resin) on a film of CCL-PAA, the exposed regions of CCL-PAA can be etched by an aqueous solution. Advantageously, the patterned, crosslinked polymer may also serve as both a reactant and a matrix for subsequent chemistry. For example, in some embodiments, the initial crosslinking cation can be exchanged for a second cation that could not be patterned photolithographically. Patterned films of CCL-PAA can also be used to host and template the reduction of metallic cations to metallic nanoparticles, and to fabricate porous, low-k dielectric substrates.

Patterning of ionic polymers

Disclosed are adhesive systems and methods of making and using such systems. Exemplary adhesive systems include protrusions and/or grooves that can interleave to form a reversible adhesive interaction.

Microadhesive systems and methods of making and using the same

Methods and apparatuses for generating electrically-conductive and/or semi-conductive films, and more specifically, methods and apparatuses for generating conductive and/or semi-conductive films having nanoscale features are provided. In one embodiment, an electrically-conductive or semi-conductive film (e.g., a gold layer of less than 50 nanometer thickness) is provided on a substrate (e.g., a poly(dimethylsiloxane) (PDMS) stamp). The substrate may optionally include patterns or features having raised and recessed portions. A first portion of the film may be removed from the substrate, e.g., by methods such as physically contacting the first portion of the film with a surface to which the first portion preferentially adheres. This process can leave a second portion of the film remaining on the substrate. In some embodiments, the second portion includes at least one region having a dimension substantially parallel to a portion of the substrate i.e., of less than 50 nanometers. The second portion of the film may be used to establish electrical communication with an electrical contact. Advantageously, electrically-conductive and/or semi-conductive films having nanoscale features can be fabricated over large areas (e.g., areas greater than 1 cm) in a single step.

Electrically-conductive and semi-conductive films

A method for fabrication of substrate having a nano-scale surface roughness is presented. The method comprises: patterning a surface of a substrate to create an array of spaced-apart regions of a light sensitive material; applying a controllable etching to the patterned surface, said controllable etching being of a predetermined duration selected so as to form a pattern with nano-scale features; and removing the light sensitive material, thereby creating a structure with the nano-scale surface roughness. Silanizing such nano-scale roughness surface with hydrophobic molecules results in the creation of super-hydrophobic properties characterized by both a large contact angle and a large tilting angle. Also, deposition of a photo-active material on the nano-scale roughness surface results in a photocathode with enhanced photoemission yield. This method also provides for fabrication of a photocathode insensitive to polarization of incident light.

Method for fabricating nano-scale patterned surfaces

Growing community of inventors

Brookline, MA, United States of America

Adam Winkleman