Patterned to your needs

1) Uniform nanocoating

A wide range of materials can be modified by Hydroix nanocoatings, also when a uniform nanocoating is needed and patterning is not required. The triggered assembly process results in strong covalent bonding of the nanocoating to the substrate. This leads to robust nanocoatings which combine excellent surface properties with high chemical and thermal stability and a high level of uniformity over the full surface.

2) local nanocoating

Hydroix technology enables the patterning of 2D and 3D nanocoatings with micrometer resolution in a fast and simple single step process.

For many applications, local control of surface properties offers great benefits. For example, by creating patterns of hydrophobic and hydrophilic areas, liquids can be confined on a surface. When applied in microfluidic devices, this allows the flow of liquids to be controlled and directed. Local control of the adsorption of biomolecules or adhesion of cells also offers interesting opportunities for applications such as cell arrays and organ-on-a-chip.


As an example, the image shows a patterned 3D nanocoating on glass consisting of 5 μm hydrophobic lines separated by 10 μm gaps. The nanocoating is highly hydrophobic (water contact angle >130°, measured on a non-patterned surface). The patterned nanocoating was analyzed by spectroscopic imaging ellipsometry, resulting in a thickness map of the surface, as shown in the image. The ellipsometric map shows that the nanocoating has a thickness of approximately 80 nm. Furthermore, the data indicate that the nanocoating has a certain degree of porosity and roughness, consistent with the very high water contact angle.

The effect of the local hydrophobic nanocoating on the wettability is visualized by microscopic investigation of the condensation pattern of water vapor on the patterned surface. The image shows that condensing water droplets align on the surface, forming a pattern with a periodicity corresponding to the nanocoating pattern (note that the scale of the ellipsometry and microscope images is different). Thus, the pattern of hydrophobic (nanocoating) and hydrophilic (glass) areas on the surface results in local control of the wettability with a micron-level spatial resolution.

Like local wettability can be controlled by patterns of hydrophobic and hydrophilic areas, the local interaction of biomolecules and cells with surfaces can be controlled by patterned anti-biofouling (protein or cell repellent) and bioadhesion promoting nanocoatings. The image shows the growth of neurons on such a patterned surface. Neurons were seeded on the surface and are localized to the nodes. Neurites grow from the nodes following the nanocoating pattern, connecting to neighbouring nodes and forming a spatially organized neuronal network.

3) Material- Selective nanoCoating

Surfix’s surface modification technology enables material-selective coating of hybrid devices, so that the surface properties of different parts of the device can be adapted to their function.

Surfaces that consist of more than one material, such as many biosensors, benefit from material-selective surface modification. The sensing element can be functionalized with a nanocoating for immobilization of bioreceptors, whereas anti-biofouling moieties can be incorporated on the surrounding surface to prevent non-specific protein adsorption. By combining both functionalities on the surface, material-selective nanocoatings enhance sensitivity and selectivity and therefore improve biosensor performance.

As an example, consider the optical ring resonator biosensor shown below, consisting of a Si3N4 waveguide (dark gray) surrounded by SiO2. Using material-selective surface modification, a bioreceptor can be immobilized on the waveguide, while an antifouling nanocoating is applied to the surrounding area. By combining both functionalities on the surface, material-selective nanocoatings enhance sensitivity and selectivity and therefore improve biosensor performance.

Application case: ring resonator

In the optical microscopy image below, the waveguide structure (inner ring) is visible inside the sensing window (outer ring). After material-selective surface modification using a fluorescent nanocoating, it is clear that only the Si3N4 waveguide has been modified.