An apparatus that is capable of propelling a gas includes a first layer and a second layer arranged in a stack, mechanism for heating and/or cooling the first layer and the second layer to form a hot layer and a cold layer, and a through hole in the stack. A surface of both the hot layer and the cold layer is exposed in an interior of the through hole. The mechanism for heating and/or cooling the first and second layers controls the hot layer to be hotter than an ambient temperature of the gas, and the cold layer to be colder than the ambient temperature of the gas.

A thermoelectric material is provided. The material can be a grain boundary modified nanocomposite that has a plurality of bismuth antimony telluride matrix grains and a plurality of zinc oxide nanoparticles within the plurality of bismuth antimony telluride matrix grains. In addition, the material has zinc antimony modified grain boundaries between the plurality of bismuth antimony telluride matrix grains.

Template-guided growth of carbon nanotubes using anodized aluminum oxide nanopore templates provides vertically aligned, untangled planarized arrays of multiwall carbon nanotubes with Ohmic back contacts. Growth by catalytic chemical vapor deposition results in multiwall carbon nanotubes with uniform diameters and crystalline quality, but varying lengths. The nanotube lengths can be trimmed to uniform heights above the template surface using ultrasonic cutting, for example. The carbon nanotube site density can be controlled by controlling the catalyst site density. Control of the carbon nanotube site density enables various applications. For example, the highest possible site density is preferred for thermal interface materials, whereas, for field emission, significantly lower site densities are preferable.

A process for producing a nanographene platelet-reinforced composite material having nanographene platelets or sheets (NGPs) as a first reinforcement phase dispersed in a matrix material and the first reinforcement phase occupies a weight fraction of 1-90% based on the total composite weight. Preferably, these NGPs, alone or in combination with a second reinforcement phase, are bonded by an adhesive and constitute a continuous 3-D network of electron- and phonon-conducting paths.

The present invention relates to CNT filled polymer composite system possessing a high thermal conductivity and high temperature stability so that it is a highly thermally conductive for use in 3D and 4D integration for joining device sub-laminate layers. The CNT/polymer composite also has a CTE close to that of Si, enabling a reduced wafer structural warping during high temperature processing cycling. The composition is tailored to be suitable for coating, curing and patterning by means conventionally known in the art.

The disclosure relates to a biomimetic limb and robot using the same. The biomimetic limb includes: an arm and a biomimetic hand connected to the arm and including at least one biomimetic finger. The biomimetic finger includes a carbon nanotube layer and a vanadium dioxide layer (VO.sub.2) layer stacked with each other. Because the drastic, reversible phase transition of VO.sub.2, the biomimetic finger has giant deformation amplitude and fast response. An robot using the biomimetic limb is also provided.

Phononic metamaterials and methods for reducing the group velocities and the thermal conductivity in at least partially crystalline base material are provided, such as for thermoelectric energy conversion. In one implementation, a method for reducing thermal conductivity through an at least partially crystalline base material is provided. In another implementation, a phononic metamaterial structure is provided. The phononic metamaterial structure in this implementation includes: an at least partially crystalline base material configured to allow a plurality of phonons to move to provide thermal conduction through the base material; and at least one material coupled (e.g., as an inclusion, extending substructure, outer matrix, a coating to heavy inner inclusion, etc.) to the at least partially crystalline base material via at least one relatively compliant or soft material (e.g., graphite, rubber or polymer). The inclusion, extending substructure matrix or coating material is configured to generate at least one vibration mode by the oscillation of at least one atom within the resonating material to interact with the plurality of phonons moving within the base material and slow group velocities of at least a portion of the interacting phonons and reduce thermal conductivity through the base material.

Phononic metamaterials and methods for reducing the group velocities and the thermal conductivity in at least partially crystalline base material are provided, such as for thermoelectric energy conversion. In one implementation, a method for reducing thermal conductivity through an at least partially crystalline base material is provided. In another implementation, a phononic metamaterial structure is provided. The phononic metamaterial structure in this implementation includes: an at least partially crystalline base material configured to allow a plurality of phonons to move to provide thermal conduction through the base material; and at least one disordered (e.g., amorphous) material coupled (e.g., as an inclusion, extending substructure, outer matrix, a coating to heavy inner inclusion, etc.) to the at least partially crystalline base material. The at least one disordered material is configured to generate at least one vibration mode by the oscillation of at least one atom within the disordered material to interact with the plurality of phonons moving within the base material and slow group velocities of at least a portion of the interacting phonons and reduce thermal conductivity through the base material.

A process for producing a nanographene platelet-reinforced composite material having nanographene platelets or sheets (NGPs) as a first reinforcement phase dispersed in a matrix material and the first reinforcement phase occupies a weight fraction of 1-90% based on the total composite weight. Preferably, these NGPs, alone or in combination with a second reinforcement phase, are bonded by an adhesive and constitute a continuous 3-D network of electron- and phonon-conducting paths.

The present invention related to CNT filled polymer composite system possessing a high thermal conductivity and high temperature stability so that it is a highly thermally conductive for use in 3D and 4D integration for joining device sub-laminate layers. The CNT/polymer composite also has a CTE close to that of Si, enabling a reduced wafer structural warping during high temperature processing cycling. The composition is tailored to be suitable for coating, curing and patterning by means conventionally known in the art.