A Singapore invention may soon be "ringing" in changes in the way commuters use one of the busiest subway systems in the United States.
Two enterprising Singapore University of Technology and Design (SUTD) students have created a ring embedded with a chip, which can replace a standard stored value card.
The "Sesame Ring" - a play on "open sesame" - has opened doors for second-year students Olivia Seow, 22, and Edward Tiong, 23.
They pitched the idea to the Massachusetts Bay Transportation Authority (MBTA) while attending a Global Leadership Programme at the Massachusetts Institute of Technology.
As soon as they arrived in June, they "hacked" the Charlie Card - the equivalent of Singapore's ez-link card - to take out the embedded chip so that it can be used in a ring.
They then sent MBTA, which has an average of 1.3 million passenger trips per weekday for its bus, train and ferry services, a video of how the ring could work at a subway station.
Within two weeks, they secured a meeting with MBTA's chief technology officer Gary Foster and other officials. The students were given 100 Charlie Cards to work on.
"We were pleasantly surprised by their openness to our request," said Ms Seow. "They were very supportive even though they are very established and we are just students."
They have started a trial in Massachusetts with 11 users. They also plan to launch the project on crowdsourcing platform Kickstarter to raise at least US$8,000 (S$10,000).
Mr Tiong said: "Many people have trouble finding their stored value cards in their bags. And when you have more than one smart card in the wallet, it does not work on the card reader."
This is not the only project the pair have worked on.
The "Sesame Ring" is an adapted version of the "Easy Ring", which is being used by some 300 students at SUTD to enter lecture halls and other facilities at its Dover campus.
Mr Tiong said they were inspired by a similar college ring called the Brass Rat at the MIT.
"But we wanted the ring to be functional," he said. "Wearable technology is a big thing now. The curriculum at SUTD gave us the ability to execute our idea."
The students, who have filed a patent for their invention, are in talks with several companies in Singapore to adapt the ring for their staff.
They also plan to pitch the idea to EZ-Link. Said Ms Seow: "We really hope the idea can be applied to the public transport system in Singapore."