Investigate how technology has influenced the development and acceptance of scientific ideas, including a case study of polymer banknotes or another Australian innovation

What this dot point is asking

NESA wants you to use polymer banknotes as a case study of Australian materials science, describe the underlying chemistry and security features, and evaluate the technology's adoption and impact. This is a strong example of an Australian-led innovation reshaping a global industry.

The answer

Australia introduced the world's first polymer banknote in 1988 (the Bicentennial ten-dollar note) and the first full polymer banknote series from 1992 to 1996. The technology was developed by CSIRO and the Reserve Bank of Australia in response to a counterfeiting problem in the late 1960s.

The problem to solve

In 1966 Australia switched from pounds to dollars. By 1967 high-quality forgeries of the new ten-dollar note were already in circulation, produced using developments in colour photocopying. The Reserve Bank asked CSIRO in 1968 to develop a banknote that would be much harder to counterfeit.

The materials science

CSIRO chemist David Solomon led the team developing biaxially-oriented polypropylene (BOPP) films.

What BOPP is.

• Polypropylene polymer (long chains of propylene monomers).
• Extruded as a film, then stretched in two perpendicular directions while heated.
• Stretching orients the polymer chains, dramatically increasing tear strength, transparency and dimensional stability.

Properties of BOPP.

• Tear-resistant.
• Transparent (can be opacified with white pigment for printing).
• Resistant to oil, water and moderate heat.
• Thin and flexible enough to handle like paper.
• Recyclable as a thermoplastic.

Security features

Polymer banknotes carry multiple anti-counterfeiting features layered together.

1. Transparent window

A clear region in the note that paper cannot reproduce. The window often contains a holographic foil image or printed micro-detail.

2. Microprinting

Text printed at scales below the resolution of consumer scanners and printers (about 0.2 mm or smaller).

3. Embossed and tactile features

Raised marks felt by visually impaired users; on the current series, these encode the denomination.

4. Optically variable ink

Ink that changes colour depending on viewing angle.

5. UV fluorescent printing

Patterns invisible in ordinary light but visible under UV.

6. Intaglio printing

Engraved-plate printing creates raised ink relief that can be felt and that resists reproduction.

7. Background detail

Microscopic patterns that scanners reproduce poorly.

These features are designed to be cumulative: defeating one is hard; defeating all is essentially impossible without industrial-scale infrastructure.

Australian rollout

• 1988. Ten-dollar Bicentennial note, the world's first polymer banknote.
• 1992 to 1996. First full polymer series ($5,$10, $20,$50, $100). Australia became the first country with an all-polymer currency.
• 2016 to 2020. Second polymer series with enhanced security and accessibility features (including tactile marks for the visually impaired).

International adoption

Over 35 countries now use polymer banknotes, including:

• Canada (2011 onwards, all denominations).
• United Kingdom (Bank of England, 2016 onwards).
• New Zealand, Singapore, Brunei, Vietnam, Romania, Mexico, Israel.

Note Printing Australia, a subsidiary of the Reserve Bank, exports both the polymer substrate and printing services internationally, making polymer banknotes a successful Australian export.

Impact

Counterfeiting

Australian counterfeit rates have remained among the lowest globally. In 2023 the rate was approximately 8 counterfeits per million notes in circulation, compared with higher rates in many paper-currency economies.

Durability

Polymer notes last three to four times longer than paper. The Reserve Bank reports that polymer note lifespan is approximately five years compared with under two years for paper.

Cost

Initial production is more expensive per note, but the longer lifespan reduces total cost.

Environment

Polymer notes are 100 per cent recyclable. At end of life they are shredded and remoulded into plastic products like garden furniture or composite building materials.

Limitations

• Polymer notes are slightly more slippery than paper, which some users find unfamiliar.
• Once damaged (torn or melted), they are harder to repair than paper.
• Older vending machines and counting equipment required upgrades.

Why this is a good case study

The polymer banknote shows:

1. A materials science problem solved by polymer chemistry. The science underpins the engineering.
2. An Australian-led innovation that became a global standard.
3. A long timeline from research to deployment (1968 to 1988, then 1988 to 1996 for full deployment).
4. A successful research-to-commercial pathway with international export potential.

Examples in context

Example 1. Counterfeit-rate evidence base. Before polymer notes were introduced in 1988, counterfeiting of Australian paper currency had risen sharply through the 1980s, with the Reserve Bank reporting an estimated 1 in every 10,000 banknotes circulating being counterfeit by mid-decade. After the 10-dollar polymer bicentennial note (1988) and the full polymer series (1992-1996) entered circulation, RBA counterfeit data showed the rate fell to around 1 in every 100,000 notes by 2000, an order-of-magnitude reduction. This empirical evidence informed the RBA's 2016-2020 next-generation banknote upgrade, which added rolling-colour effects and a tactile feature for vision-impaired users. The case shows policy-relevant primary data (counterfeit-detection logs from major banks and retailers) shaping iterative technology development.

Example 2. International diffusion of polymer technology. The polymer-substrate technology developed by CSIRO is licensed through Securency International (a Reserve Bank joint venture, now Note Printing Australia) to over 35 central banks worldwide, including the Bank of England (full series adoption from 2016 to 2021), Canada, Mexico, Romania and Vietnam. The Bank of England's switch yielded measurable durability gains (5 dollars notes lasting 2.5 times longer than paper) and a reduction in counterfeit rate. The case illustrates that scientific innovation can be exported, but also generated controversy when Securency was investigated for foreign-bribery offences (2007-2014), leading to convictions and reforms. The science is solid; the commercial implementation involved ethical and legal failures that required separate regulatory response.

Try this

Q1. Explain how biaxial orientation of polypropylene improves the mechanical properties of banknote substrate. [3 marks]

• Cue. Stretching aligns polymer chains in two perpendicular directions; produces a film strong in both axes, tear-resistant and dimensionally stable.

Q2. The RBA reports counterfeit rates of approximately 25 parts per million for polymer notes. A media article claims polymer notes are "essentially counterfeit-proof." Evaluate this claim using the data. [3 marks]

• Cue. 25 ppm is low but not zero; "essentially counterfeit-proof" overstates; sophisticated counterfeits do exist; the claim should be "substantially harder to counterfeit than paper."

Q3. A central bank in another country considers adopting Australian polymer technology. (a) Identify one primary data source the bank could use. (b) Identify one secondary source. (c) Identify one ethical or regulatory issue from the Securency case study. [2+2+2 marks]

• Cue. (a) Pilot circulation trial in one denomination; counterfeit-detection logs. (b) RBA reports, Bank of England post-implementation evaluation. (c) Robust anti-bribery and conflict-of-interest controls in commercial deals tied to public research output.