In an interesting development, Tangem has today launched what they call Smart Bank Notes in Singapore.
The Notes can be loaded using a Smartphone application and are available in denominations of 0.01and 0.05 BTC (approximately $100 and $500 today). They contain NFC chips and are designed to be handed over to any retailer just like a traditional bank note. They are in effect a secure offline paper wallet.
This could be an interesting milestone in the development of Bitcoin as a replacement for traditional currencies.
More information is available in this news release:
https://www.prnewswire.com/news-releases/tangem-launches-bitcoin-banknotes-in-singapore-300641983.html