An additive manufacturing method for fabricating 3D nanostructures is provided, charged species dispersed in a fluid are precisely arranged at nanoscale in each dimension with a configured electric field, so that the charged species are printed on a substrate to form an array of 3D nanostructures as desired. The additive manufacturing method of the present disclosure can be carried out at room temperature and atmospheric pressure without the aid of chemical reaction, laser sources, ion/electron beams, or photosensitive materials, and enables low-cost, ultra-fast printing speed, large-area, high-purity, multi-material, ultra-high-resolution and solves problems encountered in other nanofabrication techniques in making 3D nanostructures, such as a limited range of available printing materials, low resolution, slow printing speed, and one by one serial printing.

Disclosed is an apparatus for manufacturing a carbon nanotube fiber.

Provided is a composite metal-wide-bandgap semiconductor tip for scanning tunneling microscopy and/or scanning, tunneling lithography, a method of forming, and a method for using the composite metal-wide-bandgap semiconductor tip.

A method is provided for forming structures upon a substrate. The method comprises: depositing fluid onto a substrate so as to define a wetted region, the fluid containing electrically polahzable nanoparticles; applying an alternating electric field to the fluid on the region, using a first electrode and a second electrode, so that a plurality of the nanoparticles are assembled to form an elongate structure extending from the first electrode towards the second electrode; and removing the fluid such that the elongate structure remains upon the substrate.

Systems and methods of synthesizing nanoparticles on substrates using rapid, high temperature thermal shock. A method involves depositing micro-sized particles or salt precursors on a substrate, and applying a rapid, high temperature thermal pulse or shock to the micro-sized particles or the salt precursors and the substrate to cause the micro-sized particles or the salt precursors to become nanoparticles on the substrate. A system may include a rotatable member that receives a roll of a substrate sheet having micro-sized particles or salt precursors; a motor that rotates the rotatable member so as to unroll consecutive portions of the substrate sheet from the roll; and a thermal energy source that applies a short, high temperature thermal shock to consecutive portions of the substrate sheet that are unrolled from the roll by rotating the first rotatable member. Some systems and methods produce nanoparticles on existing substrate. The nanoparticles may be metallic, ceramic, inorganic, semiconductor, or compound nanoparticles. The substrate may be a carbon-based substrate, a conducting substrate, or a non-conducting substrate. The high temperature thermal shock process may be enabled by electrical Joule heating, microwave heating, thermal radiative heating, plasma heating, or laser heating.

A method for making carbon nanotube array includes depositing a catalyst layer on a substrate surface of a growth substrate, to form a composite structure. The composite structure is placed in a chamber. The carbon source gas and protective gas are supplied to the chamber, and the composite structure is heated to a first temperature, to grow a carbon nanotube array on the substrate surface. Then the carbon nanotube is oxidized.

A method for making a carbon nanotube array includes providing a substrate having a first substrate surface and a second substrate surface opposite to the first substrate surface. The substrate has a plurality of through holes spaced from each other, and each of the plurality of through holes extends from the first substrate surface to the second substrate surface. A catalyst layer is deposited on the first substrate surface, to form a composite structure. The composite structure is placed in a chamber. The carbon source gas and protective gas are supplied to the chamber, and the composite structure is heated to a first temperature, to grow a carbon nanotube array on the first substrate surface.

A method for separating a carbon nanotube array grown on a growth substrate from the growth substrate includes providing a carbon nanotube array grown on the growth substrate. The carbon nanotube array includes a plurality of carbon nanotube, each of the plurality of carbon nanotubes includes a top end and a bottom end, and the bottom end is bonded to the growth substrate. The bottom end is oxidized to form an oxidized carbon nanotube array. And then the oxidized carbon nanotube array or the growth substrate is applied to a force.

A device for making a carbon nanotube array includes a chamber, a gas diffusing unit and a gas supplying pipe. The gas diffusing unit and the gas supplying pipe are in the chamber. The gas diffusing unit is a hollow structure and defines a hole and an outlet. The gas supplying pipe includes a first end and a second end opposite to the first end. The first end extends out of the chamber. The second end is in the chamber and connected to the hole.

A method of transferring a single metal atom from a first location to a second location on the surface of a metal oxide is disclosed. The method includes obtaining a material having a first metal atom deposited on a first oxygen atom vacancy of the metal oxide and transferring the first metal atom of the metal on the first oxygen atom vacancy to a second location on the metal oxide by applying a voltage to the first metal atom. The second location can be a second metal atom on a second oxygen atom vacancy of the metal oxide, where the first and second metal atoms form a first metal atom-second metal atom species, or a metal atom of the metal oxide, where the first metal atom and the metal atom of the metal oxide forms a first metal atom-metal atom of the metal oxide species.