Dan Halpern-Leister '07 no longer fumbles for his keys when he approaches his dorm room. He touches a computer mouse mounted on the wall, then presses his forefinger to a touchpad. Inside, a computer whirs, and the door to 232 Clapp Hall unlocks.
Halpern-Leister and hallmate Alec Chapman '07 engineered the door to respond to the touch of the four roommates. The touchpad is connected to a computer that turns on a motor on the other side of the door. A red thread spool rotates, pulling a doubled fishing line through a paper-clip pulley system — and unlocking the door.
After five seconds, the computer program releases the handle, and the door is locked again.
"The point is to show people that I'm excited about something," said Halpern-Leistner, who had the idea in September and worked on it intermittently throughout fall semester. "[It's] an example of how people can put a little bit of energy into something that's not going to get them some kind of recognition or reward."
The fingerprints of Halpern-Leister and his three roommates — sophomores Yeong Dae Kwon, Marcus Lampert and Mark Salzman — are programmed as valid entries.
Other may try to enter, but the recognition is fine-tuned, neighbors said.
"Every time I go to the bathroom, I push that thing," said Michael Short '07, who lives nearby. "It hasn't let me in yet."
Halpern-Leistner was inspired to create the door-access system after seeing the inventiveness of students at the Massachusetts Institute of Technology.
"[MIT] Students can do whatever they want to the dorm," said Halpern-Leistner. "So what you get is this kind of energy and there's a lot of excitement about bringing what they learn to their living space."
Chapman joined the project in November, and the two finished on Feb. 18 after spending as much as 10 hours on some days working on the system.
"I'm impressed that they pulled it through—they were talking about it at the beginning of the year," said Marco Fossati-Bellani '07, who lives next door.
Even Lampert admitted to doubting his roommate's engineering abilities.
"I was actually sort of skeptical, just because it seems strange that you can open a door with that tiny white motor and fishing wire," Lampert said. "The physics of pulling a door open with fishing wire seemed difficult."
A challenging aspect of the project was training the mechanism to respond differently to the room's residents than to outsiders.
The device's recognition capability is made possible by a fingerprint reader, most likely designed for office employees to log onto their own computers without typing. Halpern-Leistner purchased it on EBay for less than $30.00.
It was originally designed to store only one fingerprint, but Halpern-Leistner and Chapman engineered the reader to recognize all four roommates' fingerprints. They hope they will eventually be able to extend this number to include guests as well.
While not having to carry a key might be nice, one of the roommates noted that the fingerprint recognition doesn't solve all his problems.
"It's great that we have such a high-tech device to open our door," Salzman said. "Now if only we could convince someone to come visit us . . ."
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