Not Quite Hands-Free

Posted on Sat May 3 2008

By: Hilary Feldman in Daily Green Tips, Science & Technology

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Technology marches on. And with increased realization - at least in some places and by some people - of potential environmental impacts, some things are getting more efficient. But sometimes it can be taken too far.

My mail recently included one flyer featured a scanning deadbolt lock. The predicted appeal is the elimination of keys, both for locking and unlocking doors around the home. The principle is based on biometrics. Every person has a unique fingerprint pattern created by skin ridges. The lock works by recognizing pre-set fingerprints. One new version, specifically designed for household use, can accommodate 50 different people. The system allows easy resetting, and eliminates the need for re-keying. Clear instructions indicate that multiple system administrators can be designated, and individual users can be added or deleted from the system.

Sounds convenient, right? But the locks need batteries - four AAs - to operate, with an estimated one-year battery life. An LED-lit screen is part of the mechanism. Another indicator should give warning of low batteries. But presumably frequent use of the lock will reduce battery life. And batteries are one of the major contributors to hazardous waste, with their increasing use to power cellphones, PDAs, and more. Consider that Canadians discarded about 7,500 tonnes of alkaline batteries and 2,000 tonnes of zinc-carbon batteries in 2006.

Additionally, the necessary scanning equipment and software means that, instead of a metal doorknob and bolt (which potentially could be recycled), smart locks also include electronics. So they will also contribute to e-waste when their use is outlived. Inside, the sensor itself requires a scratch-resistant coating - all those individual finger ridge features would be obscured in a smudgy picture - presumably using a durable plastic. It also has a viable operating temperature range (0 to 70 degrees Celsius, or 32 to 158 degrees Fahrenheit) - so would not work well in colder parts of Canada and other countries.

Similar fingerprint recognition technology is used in airports, police stations, and other secure buildings. In addition, you can get a USB scanner for a computer keyboard - limiting use to specific individuals rather than relying on passwords. Scanners use either optical or electrical information. Optical scanners work like digital cameras, using a CCD light sensor to record the light pattern generated by a fingerprint. Capacitance scanners use an electrical current to create an image. They tend to be more compact than optical versions. Scanners contain software that compares current patterns to stored patterns in order to authorize a match.

Although the dire scenarios sound far-fetched, there are some ways to fool scanners. Optical versions can sometimes mistake photographs for the real thing, while capacitance models may fall for a mold of a finger. Therefore, some systems suggest an additional check, such as a password (ironically).

Although fumbling for a key is awkward, and losing keys is expensive and worrisome, the new fingerprint scanners are maybe too modern for my liking. Too much electronic hardware and battery consumption seems backward - although rechargeables may alleviate this concern substantially. What a slippery slope it is, from home sensors to sensors everywhere and an Orwellian sense of being watched.