This method can be used in the fabrication of sensors, circuits, and tags to make designed resistor networks on various substrates safely, easily and efficiently. It can also be extended towards the manufacturing of solar cells by making films using the abrasion method and controlling the film’s depositional properties by modifying the surface of the substrate.
Carbon-based nanomaterials, such as carbon nanotubes and graphene, are electrically conductive materials that are ideal for chemical sensing. Sensors can be fabricated in a solvent-free, portable manner via deposition of conductive carbon nanostructures using mechanical abrasion of compressed carbon-based composites on a variety of surfaces. However, the size, thickness and distribution of the resulting conductive carbon nanostructures deposited on substrates is difficult to control and limited by the features of the substrate (e.g. surface roughness and distribution of cellulose fibers on the surface of paper).
The inventors have developed a process for the deposition of conductive layers of nanocomposites by physical abrasion onto patterned surfaces. This method offers precise control over location, thickness, and other structural features of the resulting nanostructures, which greatly extends its capabilities for the fabrication of functional sensors, circuits and tags. Sensors are fabricated by abrasion of compressed single-walled carbon nanotubes (SWCNTs) and compressed graphite onto laser-etched plastic and paper. This approach produces sensors that are able to detect a wide variety of analytes in part-per-million concentrations.
Other methods, such as chemical etching, scratching, and nanoindentation can be used to generate patterns that guide abrasion of carbon-based materials into pre-defined locations. The choice of substrate includes glass, polymers of any kind, paper, metal, skin, leaves and wood, among others. This method of selective deposition of materials can be extended to small molecules, metals, nanoparticles, and conductive polymers.
- Enables parallel fabrication of conductive micro- and nanostructures with precise control over structural features
- Method can be used on a wide range of substrates
- Simple and inexpensive fabrication without need for specialized equipment or facilities
- Portable, efficient, eco-friendly and scalable approach