Printed, Flexible and Stretchable
Electronics

CALL FOR PARTICIPATION

Technical Work Area 36

Project 4

Measurement of Lateral Resolution of Raman
Microscopy with Nanowire Artefacts
Objectives
Thisprojectwill
assesstheperformance characteristics of amethod for measuring lateral resolution
in Raman microscopy through anInterlaboratory
Comparison.
The
proposed method uses traceably
characterised nanowires as calibration
artefacts.

Background
Raman microscopy is a widely usedtechnique for chemically sensitive
mapping of samples. This is typicallyachieved by coupling a Raman
spectrometerwithaconfocal
microscope and scanning across asample of interest to construct a pixelby-pixel image.
The spatial resolution of Raman
microscopy is an important parameterfor characterising the performance of an
instrument as well as for quantitativedescriptionofsamplefeatures.
However, such measurements of spatial
resolution require suitable artefacts,
which are yet to be developed.
Specifically, this project will consider
lateral resolution measurements using
inorganic nanowires and the line-spreadfunction (LSF) method. A unique featureof these samples is that individual

nanowires can be easily and uniquely
identified, which enables traceablecharacterisation
withmetrologicalatomic force microscopy (AFM).

Standardisation Needs

Optical microscope image showing example ofisolated inorganic nanowire artefact.

Existing standards (ISO 18337:2015,ISO 18516:2019) relate to thedetermination of lateral resolution in
general, and also to the specific case ofmeasurement of lateral resolution forconfocal fluorescencemicroscopy,
which is closely related to confocal
Raman microscopy. These standards
describe
generalandspecificrequirements of artefacts for lateral
resolution methods, but do not address
suitability for Raman measurements.

Deliverables andDissemination

Work ProgrammeThis activity has been initiated throughthe EMPIR 16ENG03 HyMet project.
Participants in the interlaboratorycomparison will fund their own
involvement (approx. 3 days’ work).

• Develop protocol and finalise
artefact design• Prepare samples for round-robin• Traceable dimensional
characterisation at NPL• Round-robin interlaboratory
measurements• Data analysis, evaluation andreporting

Report will evaluate the suitability ofcandidate physical standard and guide
further development. Results will be
published in peer-reviewed journal
and are expected to contribute to adocumentary standard under ISO TC
201.

Funding

International Participation
Current participants represent the UK,France, Denmark, Italy, Germany, USA,Canada, Brazil, Korea, Japan, and China.
This project is run jointly with VAMAS
TWA 42 ‘Raman Spectroscopy andMicroscopy’.

Raman scattering intensity profile across nanowire of known
dimension provides a measure of lateral resolution.

StatusSamples dispatched to participants andmeasurements in progress.
For more information on
participation, please contact:

Dr. Sebastian Wood
Dr. Fernando Castro
Project Leaders
National Physical Laboratory, UK

Email: sebastian.wood@npl.co.uk
Email: fernando.castro@npl.co.uk

Erlon H Martins Ferreira

Chair, VAMAS TWA 42
Inmetro, Brazil
Email: ehferreira@inmetro.gov.br

www.vamas.org
August 2022