Formable to 3D shapes. Good display readability.
Canatu has developed a new material, Carbon NanoBud®, which is a hybrid of Carbon Nanotubes and Fullerenes. Canatu has additionally developed a new component manufacturing method called Direct Dry Printing® (DDP) which allows synthesis and direct patterned deposition of NanoBud® films on any substrate material even at room temperature.
The CNB™ films and sensors manufactured from the NanoBud® material have a unique feature being formable to any 3D shape with high stretch rate and small bending radius. Due to high transparency, low haze, and almost no reflections, CNB™ films enable touch displays with no compromise in display readability even in bright ambients.
Formable to 3D shapes
Canatu CNB films and sensors can be thermoformed into extreme shapes. CNB films are highly stretchable, as Carbon NanoBud material stretches more than 200%. The maximum stretch rate depends on the substrate material. The CNB films enable deep draws and sharp bends: bending radius can be less than 1mm.
Forming and molding
The CNB films and sensors can be thermoformed, vacuum formed and pressure formed according to standard industrial processes. CNB sensors can also be in-molded with multiple resins as well as laminated between different materials and LOCA bonded to glass or display surface.
The touch sensor typically consists of a plastic substrate with one or more patterned CNB transparent conductor layers and auxiliary film layers such as patterned metallic conductor traces. Touch modules with cover glass, mechanics, controller IC, and electronics on the flexible circuit board are manufactured and sold by Canatu’s touch module customers. Canatu’s sensors are typically designed to meet custom specifications by Original Equipment Manufacturers and Canatu’s direct customers.
CNB sensors are built using 1 sensor layer or 2 sensor layers
1-layer sensor construction is used for switches, buttons, sliders, wheels (mutual or self capacitance)
2-layer sensors are for multitouch, with separate transmit and receive layers (mutual capacitance)
CNB Touch Sensors are formed and back-molded to make CNB touch modules.
Two special features of Carbon NanoBud® material make CNB™ films great for on-display use:
- CNB™ Film is color-neutral, with almost flat transmittance spectrum. As a result, display colors do not get distorted in the CNB™ sensor. This is particularly important for white color as even small color changes of white are easily discernible by the eye.
- Carbon NanoBud® material is pure black: if light falls directly on the NanoBud molecule, it gets totally absorbed, i.e. no reflection. Hence, in an optimized stack with high-performance substrates and bonding layers, CNB Films and Sensors do not reflect any light and the haze is zero. In practice, CNB sensor reflection is typically 0.0…0.3% and haze is 0.1… 0.5%, both very low values. The result is touch displays with deep black and high contrast even in bright ambient conditions.
Canatu has developed a new material, the Carbon NanoBud®, which is a hybrid of single wall Carbon Nanotubes and Fullerenes. The hybridization is achieved directly in the material synthesis process and the resulting material combines the best features of both Fullerenes and Nanotubes. NanoBud enables a variety of new components and applications to be developed.
NanoBud has tunable electrical conductivity, high strength, low density, high thermal and mechanical stability and high electrical and thermal conductivity like traditional carbon Nanotubes, but also high reactivity, low work function and chemical functionalizability like Fullerenes. In addition, they have been shown to be much superior field emitters than traditional nanotubes and have the added benefit that they need not be aligned for the purpose. This makes NanoBuds® ideal for a tremendous range of applications.
Carbon NanoBud® molecule
Unique properties of NanoBud
When Carbon NanoBuds are deposited on a substrate using DDP method they form a random network of NanoBud molecules (see image). In commercial CNB films, most of the area on the substrate is “empty”, allowing light to pass through freely. On those areas where there are NanoBud molecules, light gets absorbed without any reflection. These two features result in the amazing simultaneous combination of high transmittance and low reflection/low haze in the CNB films.
The Nanotube part of the Carbon NanoBuds is single-wall type, making the molecule flexible. In contrast, multi-wall Nanotubes are rigid. During CNB film deposition in DDP, the NanoBuds fall in a curved and curled manner on the substrate. When CNB films are stretched, the NanoBud molecules get straightened and they slide over each other. This is the secret behind the unique stretchability of the CNB films. In practice, the substrate material mechanical properties set the limit for the CNB film stretchability, not the Carbon NanoBud material.
Transmission electron micrograph of a
Carbon NanoBud® network in the CNB™ Film
Direct Dry Printing®
Canatu has developed a new thin-film component manufacturing method called Direct Dry Printing® (DDP). Direct Dry Printing combines into a single production step 1) a synthesis process that leads into an aerosol flow of the carbon nanomaterial molecules, 2) direct printing and 3) concomitant coarse patterning of the nanomaterial films. NanoBud® films can be direct pattern deposited on almost any substrate material at room temperature. Canatu patented innovations remove all of the existing bottlenecks to the commercialization of carbon nanotechnology.
The combination of Canatu’s unique patented synthesis method, which produces clean, unbundled, high crystallinity Carbon NanoBuds directly in the gas phase, and Canatu’s efficient Direct Dry Printing method, which allows homogenous or patterned deposition on almost any substrate at room temperature and pressure, results in a simple, scalable, one-step, low cost component manufacturing process.
Canatu uses its Direct Dry Printing method in both sheet and Roll-to-Roll implementations. Hence, CNB films are available in sheet form and in rolls.
Unlike traditional batch methods which start with nanotube powders and require multiple, complex and expensive processing steps to achieve deposits, Canatu’s methods start with better material and maintains these material qualities on the substrate. No material degrading, hazardous, acid treatments, sonification, surfactants or functionalizations are required. With this method, a wide variety of high performance components can be easily produced in a more rapid, economical and environmentally sound procedure.
Compared to other techniques, such as nanomaterial printing using inks, Canatu’s manufacturing method reduces the number of steps to make deposits and increases the quality and performance of the final products. The main raw material is carbon containing gas. In some cases, waste products from other industrial processes can be recycled to produce Canatu’s carbon nanomaterials and making ours a very environmentally friendly technology.