IP Information & News

Size matters — patenting at the nanoscale

Nanotechnology is based on understanding and controlling properties at the nanoscale to develop functional products. There are huge developments underway in the ‘nano’ space, with cosmetics and sun creams being key examples of product areas where the technology is already being commercialised. In fact, according to StatNano, 13,046 published patent applications relating to nanotechnology inventions were filed at the United States Patent and Trademark Office (USPTO) and the European Patent Office (EPO) in 2018.

New kid on the sunblock

The chemical compound Methylene Bis-Benzotriazolyl Tetramethylbutylphenol (or, thankfully, MBBT for short) is the latest chemical to be authorised by the European Union (EU) in the form of nanoparticles for use as an ultra-violet (UV) filter in cosmetics and sunscreens, in a concentration of up to 10% w/w.


MBBT received approval as a cosmetic UV active ingredient in 2000 and has been widely used ever since. However, in Europe as well as many other regulatory jurisdictions, additional approval is required to use the nanoscale version of the material, due to safety concerns relating to human health. To date, only three other nanoscale UV filters have been approved for cosmetic use: titanium dioxide, zinc oxide and tri-biphenyl triazine.

What’s a nanomaterial, and what’s going on at the nanoscale?

A nanomaterial can be defined as a material with a particle size between one and 100 nanometers. It can be difficult to comprehend just how small the nanoscale is — one nanometer is a billionth of a meter. A good analogy is to imagine that a single nanoparticle is the size of a football. This would mean that your actual football would be the size of the earth.

At the nanoscale, materials can have distinct and sometimes surprising physical, chemical and biological properties that differ from the bulk material. For example, the UV absorption range of MBBT increases with decreasing particle size, making it a more effective sunscreen. Zinc oxide, another UV absorber, is usually white and chalky but becomes clear on the nanoscale, making it more desirable for cosmetics. Interestingly, a nanoparticle of gold will appear red or purple rather than the traditional metallic colour, and the colour can be tuned depending on the environment surrounding the nanoparticle. Nanoscale drug-delivery systems allow access into cells and cellular compartments such as the nucleus, which just isn’t possible with larger-scale delivery systems.

The nanoscale patenting problem — considerations for inventors

Given the need for additional regulatory approval for nanoscale materials, you may be asking the question — if a nanoscale material is considered to be a ‘new’ product, requiring separate regulatory approval, can patent protection be obtained for a nanomaterial despite the material itself having been disclosed years before? Would a nanoscale material infringe the claim of a granted patent directed to the material per se?

Certainly there are many unique issues to consider when securing patent protection for nanotechnology inventions, as well as establishing whether you are ‘free to operate’. The basic requirements for obtaining a patent are that the invention must be novel, inventive and industrially applicable. The invention must also be sufficiently disclosed such that the average skilled person can carry out the invention across the whole of the claimed range.


Novelty is acknowledged in patent applications if there’s a difference between the invention and the known art. Generally speaking, a device or material that’s simply smaller in size than a previously known device or material won’t meet the requirement of novelty.

However, in the UK and at the EPO, novelty can be acknowledged in the selection of individual elements, sub-sets or sub-ranges which haven’t been explicitly mentioned within a larger known set or range. This is referred to in both UK and EPO law as a “selection invention”.

Since nanotechnology inventions will often be defined by a parametric range (e.g. a material or device with a 1-100 nm size range), the question of novelty is commonly focussed on sub-range size selections during examination. For example, novelty of the nanoscale device or material may be assessed with respect to prior art that defines the device or material without any definition of size, or with an open-ended size range incorporating the nanoscale material — for example, a size range of less than 1 mm.

In such cases, the EPO has a specific test for establishing whether the size sub-range is novel over the prior art. A nanoscale device or material will be considered novel if the selected size range is:

(1) narrow compared to the known prior art size range;

(2) sufficiently far removed from specific examples disclosed in the prior art and end points of the prior art size range; and

(3) not an arbitrary miniaturisation of the prior art, but another invention (i.e. a new technical teaching — also see ‘inventive step’ below).

For example, in T 547/99, the Technical Board of Appeals (TBA) of the EPO held that a prior patent that disclosed polymer nanoparticles larger than 111 nanometers did not destroy the novelty of nanoparticles smaller than 100 nanometers.

The UK has similar considerations for examining sub-ranges.

Inventive step

Inventive step is assessed differently depending on the patent law jurisdiction, but the general question for the assessment of inventive step is: would a person skilled in the art, who is familiar with the prior art, have arrived at the solution provided by the invention?

For nanotechnology inventions, the question often comes down to whether the reduction in size is arbitrary, or whether it’s connected to a new technical advantage.


In the UK and at the EPO, inventive step may be acknowledged for a smaller version of a known device or material where it shows a surprising technical effect and if no hints exist in the prior art that lead the skilled person to make the claimed selection. The surprising technical effect could either be new or the same as that of the larger device, but exhibited to a greater extent, provided that the effect is not an obvious extension from the teachings of the prior art.

For example, in T 552/00, the Technical Board of Appeals (TBA) of the EPO held that a vaccine adjuvant that differed only from the known adjuvant by its size (<120 nm) was inventive because it unexpectedly improved the properties of the adjuvant — and there was nothing in the prior art to suggest that reducing the size could lead to this advantage.

Commercial considerations and recommendations

Nanotechnology inventions can span multiple scientific and engineering fields, making enforcement, patentability searching and freedom-to-operate clearance difficult (and of course, expensive). For example, take a patent granted to a carbon nanotube which has applications in a wide range of fields from telecommunications to pharmaceuticals. The patentee may only wish to work in one of these fields, but its patent may prevent third parties from using the technology in other fields. Furthermore, a third party may not be aware of the patent if it has only conducted a freedom-to-operate search in its particular field of interest — and vice versa for the patentee looking to enforce its patent.

The cross-industry nature of nanotechnology inventions can also make it difficult to allocate a patent examiner with the appropriate technical expertise, as well as to classify applications into a technical search field so that they can be discovered by interested third parties. To assist examiners and third parties with prior art searching, patent offices have unique search identifiers for applications relating to nanotechnology. At the EPO, the nanotechnology classifier is B82Y. This classification can be combined with other classifications or keyword search terms to narrow the search to a particular technology or application.

The legal landscape for nanotechnological inventions can also be complex due to the common reliance on ‘selection inventions’, which can lead to the existence of granted patents with overlapping scope.

As always (and particularly in the nanotechnology field), we recommend sourcing a comprehensive freedom-to-operate patent search before developing and commercialising a new product which has a nanotechnology aspect. New entrants to a market should also be prepared to find that they may need to obtain a licence from a third party even if they own a granted patent covering their commercial activity. Additionally, the patentability of any new developments in the nanotechnology fields should be evaluated not only for their potential market exclusivity, but also for licensing and cross-licensing potential. Conducting proper due diligence and developing a robust licensing strategy could avoid potential litigation costs further down the line.

If you’re an inventor or user of nanotechnology and would like to discuss intellectual property issues in more detail, feel free to get in touch with Dr Simon Mitchell at sjm@udl.co.uk.

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