Ink-credible: Developing sensors utilising ink jet printing for the Mary Rose Museum (Spotlight on SEAHA)

This month, we will be publishing a series of posts from SEAHA (Science and Engineering in Arts, Heritage and Archaeology) students on their research, in the run-up to the 3rd International SEAHA Conference in June. First up, Sarah Hunt talks about her project developing acid sensors for the Mary Rose Museum – using ink jet printing.

The aim of my project is to develop a real time acetic acid sensor to be trialled in display cases at the Mary Rose Museum, Portsmouth. I will utilise piezoelectric quartz crystal (PQCs) technology, which has the benefit of being small and affordable.

PQCs are electronic components that act as micro-balances: the quartz crystal is sensitive to very small changes in mass that occur on its surface and will result in a measurable signal, observed as a frequency change. Hence if a coating that interacts with a pollutant of interest, for example acetic acid, is applied to the surface of a PQC, a measurable response will be observed. The resulting system could be used to affordably monitor that pollutant.

The method used to apply the thin coating onto the PQC needs to create a uniform layer, with good control over the mass of coating deposited. I am currently trialling ink jet printing as a method to deposit the thin film, as this method can offer very fine control over the location and amount of deposited material (fig. 1 and 2).

fig 1a
Fig. 1: The research printer used to coat PQCs in a thin film. It consists of a metal stage, which the PQC is attached to during printing; four print heads, which are connected to different four fluid reservoirs; a vertical camera to help pinpoint the required printing locations; and a horizontal camera with a strobing LED opposite to image the drops during jetting.
fig 1b
Fig. 2: An image captured from the horizontal camera during jetting of a lead oxide solution.

Inkjet printing can be performed with a wide range of materials in solution or suspension, including metal nanoparticles, hence this technique could be used for a wide range of coatings. It can also be used to create thin films of different shapes, such as circular patterns, and hence apply a film over the entirety of the PQC surface (fig. 3 & 4).

fig 2
Fig. 3: This shows two PQCs, the one on the left is uncoated. The PQC on the right was imaged after printing a polymer resin in a square array onto its surface.
fig 3
Fig. 4: A circular printed array

This project is still in its early stages – however, if a real time acetic acid sensor can be developed, with good accuracy and low detection limits, it will be highly beneficial for any museum concerned about acetic acids during storage and display of artefacts. The Mary Rose Museum, which houses a large collection of polyethylene glycol (PEG) treated waterlogged wood, will gain a better understanding of organic acid emissions from PEG treated wood and the implications of this on the collection.

Moreover, if this project is successful, I am hopeful that further Heritage Science research will be performed utilising PQCs, taking advantage of their adaptability by changing the coating applied. Early warning dosimeters for specific heritage materials could be developed, or even personalised air quality sensors that are sensitive to pollutants chosen by the museum. Perhaps this is a long way off, but quite an exciting proposal.

Alongside Heritage Science, environmental sensors are widely used in society, particularly with the increasing awareness of indoor air quality and health. Advances in PQC sensors from Heritage Science could be beneficial for this industry.

Want to find out more?
I will have a poster at the SEAHA 2017, Brighton – come and chat to me about it.
Twitter: @Sarah_JayneHunt

The 3rd International Conference on Science and Engineering in Arts, Heritage and Archaeology (SEAHA) will take place on 19-20 June 2017 at the University of Brighton. Click here to view the programme of themed sessions and flash presentations, and here to register.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s