The fabrication of AFM probes gives us a wide range of expertise which can be exploited in other areas. One of the more unusual, bespoke enquiries we received was to help manufacture a key component of a new diagnostic medical device.

The approach was made by Dr John Day and Dr David Megson-Smith, University of Bristol Interface Analysis Centre (IAC) - Applied Optics Group, who were lead development scientists on a project to transform the diagnosis of cancer of the oesophagus.

Cancer of the Oesophagus

Cancer of the oesophagus is the 5th most common cancer. It is often discovered late and is one of the most likely to cause death, with only around 15% of patients surviving 5 years from their first diagnosis.

The project, which kicked off in 2016 between the University of Exeter, University of Bristol and Gloucestershire Hospitals NHS Foundation Trust, was to manufacture a ground breaking medical device to assist in the assessment of Barrett’s Oesophagus and Oesophagial cancer. Key to the remit was the production of a surgical device that could be mass produced and be able to help medical professionals in the accurate and speedy diagnosis of these cancers.

“To manufacture the diagnostic device we needed a way of producing optical motherboards that were commercially viable and micron accurate,” says Dr John Day.

“Initially we investigated using ultra high resolution 3D printing to produce the optical motherboards but we found that the reproducibility and accuracy of the product was insufficient for our needs.”

Silicon Wafer Production

Many years previously John had looked into the possibility of using silicon to produce motherboards and had demonstrated it was possible to align silicon and fibre optics to cylindrical grin lenses with good results.

“As we also needed to include non-cylindrical optical components, specifically dichroic mirrors and filters onto the motherboard we didn’t know if silicon was an option. It certainly wasn’t possible using traditional silicon wet-etch techniques alone, but we thought it was worth exploring the notion further with an expert in the area of silicon wafer production,” says Dr David Megson-Smith.

“Knowing the expertise NuNano have in the manufacture of silicon wafers for the production of AFM probes, we decided to approach James and explain our problem to him.”

John and Dave’s idea was to use optical motherboards made from silicon, but they didn’t know if it was feasible. NuNano MD and founder Dr James Vicary proposed conducting a short ‘proof-of-principle’ service to demonstrate whether motherboards capable of simultaneously locating cylindrical and orthogonal optical components could be produced.

Rigour and Scaleability

“There were significant unforeseen challenges that presented themselves,” says John, “however the NuNano team worked diligently to develop a process that is now both repeatable and rigorous in its product quality,”

The impact of NuNano’s work on the project was proof of scalability. Whereas previously it would have taken an hour to produce a single optical motherboard using high resolution 3D printing, the NuNano technique demonstrated it was possible to obtain silicon wafers which each yield 100 motherboards.

“Due to the nature of silicon fabrication and its inherent scalability hundreds can easily become thousands or tens of thousands,” says David. “This would never have been possible using the 3D printing technique which gives the silicon optical motherboards a very strong commercial standing.”

Bespoke Service

“NuNano provided a really great bespoke service,” says John. “We came to them with a unique problem, one that we weren’t sure could even be resolved by the method we were looking to trial.”

“They were able to provide really good expertise - both from the initial conversations with James as we discussed and designed the process, through to the more detailed work once the project was underway The process engineer assigned to our project was second to none and was able to provide us with invaluable advice to help us overcome a significant technological hurdle.”

The project has been through various rounds of in human trials and is continuing its journey through the Medicines and Healthcare products Regularly Agency (MHRA) assessment process. Alongside the project team, we eagerly await the outcome to see what happens next with this revolutionary diagnostic device.

Other links to public domain information about the project

https://clinicaltrials.gov/ct2/show/NCT03468634