Abstract: Disclosed are methods and systems for measuring and managing swelling of rechargeable batteries in situ. Some implementations involve using capacity fade or state of health of rechargeable batteries to estimate swelling of the rechargeable batteries. Some implementations provide methods and systems for measuring battery swelling based on inductive or capacitive coupling between sensors and the battery. Some implementations provide means to manage or reduce swelling of rechargeable batteries by applying adaptive charging with consideration of battery swelling.

Abstract: Disclosed are methods and systems for measuring and managing swelling of rechargeable batteries in situ. Some implementations involve using capacity fade or state of health of rechargeable batteries to estimate swelling of the rechargeable batteries. Some implementations provide methods and systems for measuring battery swelling based on inductive or capacitive coupling between sensors and the battery. Some implementations provide means to manage or reduce swelling of rechargeable batteries by applying adaptive charging with consideration of battery swelling.

Abstract: Methods for forming freestanding objects primarily comprising aligned carbon nanotubes, as well as the objects made by these methods, are provided. Arrays of generally aligned carbon nanotubes are first synthesized on a substrate then released from the substrate and densified, maintaining the aligned arrangement. These densified arrays can take the form of thin strips which can be joined together, for example by lamination, to form larger objects of arbitrary size. These objects can be further cut or otherwise machined to desired dimensions and shapes. Release from the substrate can be accomplished mechanically, such as by shearing, or chemically, such as by etching. Densification can be accomplished, for example, through compaction or by taking advantage of capillary forces. In the latter case, an array is first wetted with a fluid and then dried. As the fluid is removed, capillary forces draw the nanotubes closer together.

Abstract: A catalyst material for carbon nanotube synthesis includes a uniform dispersion of host particles on a substrate. The host particles themselves include catalyst nanoparticles that are effective to catalyze nanotube syntheses reactions and provide nucleation sites. Methods for preparing catalyst materials include co-sputtering a catalytic species and a host species to form a precursor thin film on a substrate, followed by an oxidation reaction of the precursor thin film in air. The precursor thin film can be patterned on the substrate to limit the locations of the catalyst material to well-defined areas. Methods for nanotube synthesis employ CVD in conjunction with the catalyst materials of the invention. During the synthesis, the catalyst nanoparticles catalyze carbon nanotubes to grown from a carbon-containing gas.

Abstract: A catalyst material for carbon nanotube synthesis includes a uniform dispersion of host particles on a substrate. The host particles themselves include catalyst nanoparticles that are effective to catalyze nanotube syntheses reactions and provide nucleation sites. Methods for preparing catalyst materials include co-sputtering a catalytic species and a host species to form a precursor thin film on a substrate, followed by an oxidation reaction of the precursor thin film in air. The precursor thin film can be patterned on the substrate to limit the locations of the catalyst material to well-defined areas. Methods for nanotube synthesis employ CVD in conjunction with the catalyst materials of the invention. During the synthesis, the catalyst nanoparticles catalyze carbon nanotubes to grown from a carbon-containing gas.

Abstract: Thermal pads, including free-standing examples, are provided for dissipating heat from a heat source like a semiconductor die to a heat management aid such as a heat sink. The thermal pads include a sheet of vertically aligned carbon nanotubes and a surface layer. One such surface layer has a thickness of less than 500 microns. Another includes a metal layer having a thickness of less than 500 microns and an intermediate layer attaching the metal layer to the sheet of carbon nanotubes.

Abstract: Methods for forming thermal pads including arrays of vertically aligned carbon nanotubes are provided. The thermal pads are formed on various substrates, including foils, thin self-supporting polished metals, semiconductor dies, heat management aids, and lead frames. The arrays are growth from a catalyst layer disposed on the substrate. Forming the array can include leaving the ends of the nanotubes unfinished, attaching a foil thereto, or coating the ends with a metal layer. The metal layer coating can then be polished to a desired smoothness. The array can be filled with a matrix material, only partially filled, or left unfilled. Where the substrate is a foil, the method can be a continuous process where foil is taken from a roll and fed through a series of formation steps. Where the substrate is a lead frame, heating can be generated by applying an current to a pad of the lead frame.

Abstract: Methods for producing carbon nanotube thermal pads comprise forming an array of carbon nanotubes on a catalyst layer on a substrate and releasing the array from the substrate. The carbon nanotubes are grown so that they are generally vertically aligned relative to the substrate. Releasing the array can include dissolving the substrate. Alternately, a release layer between the substrate and the catalyst layer can be employed. The release layer can be chemically removed, or can provide a low-strength interface that is easily pulled apart or sheared.

Abstract: Devices and methods for their manufacture are provided. The devices, such as packaged semiconductors, include thermal pads of vertically aligned carbon nanotubes to transport heat from a heat source such as a semiconductor die, to or between thermal management aids such as a heat spreader or heat sink. Some devices include spacers between the heat spreader and the heat sink to protect the thermal pad during assembly. Other devices include thermal pads that have surface layers matched by composition to the surfaces of the opposing surfaces, thus silicon on one side and a metal on the other. In some devices, the ends of the carbon nanotubes extend into the surface of the thermal management aid. Methods for bonding the thermal pads include bonding surface layers, as well as exposed carbon nanotubes, to opposing surfaces.

Abstract: Methods for joining two objects through the growth of carbon nanotubes from one or both of two opposing surfaces of the two objects, and interfaces formed between the two objects, are provided. Carbon nanotubes grown from both of the opposing surfaces can interdigitate to secure the two objects together. A metal layer can also be placed on one of the opposing surfaces such that carbon nanotubes growing from the other opposing surface bond with the metal layer. In addition to the mechanical bond, the carbon nanotubes can also provide thermal and electrical conductivity between the objects.

Abstract: A thermal interface includes an array of generally aligned carbon nanotubes joined to a surface with a metal layer. The array of carbon nanotubes includes a coating on the ends of the carbon nanotubes for improved wetting of the metal layer to the ends of the carbon nanotubes so that the thermal resistance at the interface between the carbon nanotubes ends and the metal is reduced. A semiconductor device that employs a thermal interface of the invention, and a method for fabricating the thermal interfaces are also provided.

Abstract: A catalyst material for carbon nanotube synthesis includes a uniform dispersion of host particles on a substrate. The host particles themselves include catalyst nanoparticles that are effective to catalyze nanotube syntheses reactions and provide nucleation sites. Methods for preparing a catalyst material includes co-sputtering a catalytic species and a host species to directly form the catalyst material. Methods for synthesizing generally aligned nanotubes are also provided. In these methods host particles comprise alumina and the catalyst nanoparticles comprise iron. Also in these methods nanotube synthesis is achieved in an atmosphere including a carbon-containing gas and water vapor.

Abstract: A catalyst material for carbon nanotube synthesis includes a uniform dispersion of host particles on a substrate. The host particles themselves include catalyst nanoparticles that are effective to catalyze nanotube syntheses reactions and provide nucleation sites. Methods for preparing catalyst materials include co-sputtering a catalytic species and a host species to form a precursor thin film on a substrate, followed by an oxidation reaction of the precursor thin film in air. The precursor thin film can be patterned on the substrate to limit the locations of the catalyst material to well-defined areas. Methods for nanotube synthesis employ CVD in conjunction with the catalyst materials of the invention. During the synthesis, the catalyst nanoparticles catalyze carbon nanotubes to grown from a carbon-containing gas.

Abstract: In one embodiment, the present invention provides for a nanotube-based sensor for detecting a biomolecule comprising one or a plurality of nanotubes, a first electrode and a second electrode connected to said nanotubes, a microfluidic system, and a plurality of immobilized biomolecules, wherein said plurality of immobilized biomolecules are immobilized on said plurality of nanotubes, said plurality of nanotubes are integrated to said microfluidic system, and said first electrode and said second electrode are connected to provide to electrical readout. In another embodiment, said plurality of immobilized biomolecules are immobilized on said substrate or said electrodes or the said microfluidics system. In another embodiment, the sensors are integrated to provide an array of sensors. The present invention further provides for methods to detect a biomolecule using the nanotube-based sensors or arrays of sensors.

Abstract: A cathode has electropositive atoms directly bonded to a carbon-containing substrate. Preferably, the substrate comprises diamond or diamond-like (sp.sup.3) carbon, and the electropositive atoms are Cs. The cathode displays superior efficiency and durability. In one embodiment, the cathode has a negative electron affinity (NEA). The cathode can be used for field emission, thermionic emission, or photoemission. Upon exposure to air or oxygen, the cathode performance can be restored by annealing or other methods. Applications include detectors, electron multipliers, sensors, imaging systems, and displays, particularly flat panel displays.