Abstract: 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.

Abstract: The present invention is directed to adhesive systems and methods of making and using such systems. Exemplary adhesive systems comprise protrusions and/or grooves that can interleave to form a reversible adhesive interaction.

Abstract: 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+, Ca2+, Pd2+, Al3+, La3+, and Ti4+) 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.

Abstract: Animal litters and methods of making and using such litters are disclosed herein. The animal litters comprise (a) a plurality of absorbent particles comprising (i) a non-swelling particle and (ii) a clumping material coated on the non-swelling particle and (b) a plurality of one or more filler particles that are not associated with the absorbent particles. The filler particles provide additional functionality to the litters, e.g., controlling odor, absorbing moisture, releasing fragrance, controlling microorganisms, controlling dust, reducing density, reducing weight, and combinations thereof. The litters are made by producing the absorbent particles using conventional means and combining the absorbent particles with one or more filler particles that impart the desired characteristic to the litters.

Abstract: 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.

Abstract: 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.

Abstract: The present invention is directed to articles comprising smudge-resistant anti-reflective surfaces, and products and devices comprising the articles.

Abstract: 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.

Abstract: The present invention is directed to passive thermal monitoring devices, and methods of making and using the passive thermal monitoring devices.

Abstract: The invention provides animal litters and methods of making and using such litters. The animal litters comprise (a) a plurality of absorbent particles comprising (i) a non-swelling particle and (ii) a clumping material coated on the non-swelling particle and (b) a plurality of one or more filler particles that are not associated with the absorbent particles. The filler particles provide additional functionality to the litters, e.g., controlling odor, absorbing moisture, releasing fragrance, controlling microorganisms, controlling dust, reducing density, reducing weight, and combinations thereof. The litters are made by producing the absorbent particles using conventional means and combining the absorbent particles with one or more filler particles that impart the desired characteristic to the litters.

Abstract: The present invention is directed to adhesive systems and methods of making and using such systems. Exemplary adhesive systems comprise protrusions and/or grooves that can interleave to form a reversible adhesive interaction.

Abstract: The present invention is directed to adhesive systems and methods of making and using such systems. Exemplary adhesive systems comprise protrusions and/or grooves that can interleave to form a reversible adhesive interaction.

Abstract: 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.

Abstract: 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.

Abstract: 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+, Ca2+, Pd2+, Al3+, La3+, and Ti4+) 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.

Abstract: 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.

Abstract: A self-assembled article includes a surface comprising an chemical functionality having an immobilized charge; and a plurality of particles assembled on the surface of the core, said particles having a surface comprising an immobilized chemical functionality of a charge opposite that of the core.