Electrochromic Visor Aids Motorcyclists

opticsorg writes "A team from Uppsala University and the firm Chromogenics Sweden AB have developed a flexible electrochromic foil and integrated it into the visor of a motorcycle helmet. The result is a visor that the rider can electronically switch between dark and transparent states. Applying a voltage of about 1V to the initially transparent visor causes it to darken in a matter of seconds. When the voltage is turned off, the visor keeps its properties, while applying a reverse voltage makes it revert to its natural lightly tinted state."

Comments

MIT and LCDs

[Mr. Darl McBride]

Something similar was tried as a studen project at MIT. They used a flexible LCD panel, fixed over the faceplate of a motorcycle helmet. It had the desired effect, letting them dim the view during the day and lighten it at night, all with just three AA batteries, a rocker switch, and a simple 555 strobing timer circuit.

The project lead didn't manage to show up for the project class presentation however; he'd wiped out on the way to school.

Apparently on a colder morning, the LCD began to dim on its own as the cold wind affected the crystals, making them darken slowly and subtly. By the time he consciously realized he wasn't seeing well, he'd already skidded into the back of a flatbed truck!

I guess the simple lessons can be painful ones at MIT.

Forget motorcycles... windows!

[Tom7]

Sweet. I've always wanted window panes that I can "turn off", and this is getting pretty close. Liquid crystals aren't so good because you need to keep the voltage applied in order to keep the crystals aligned.

been out for years

[austad]

Welding visors have had this for years. Kind of interesting it's only being used now in helmets.

The welding visors ran about $200 to $300 last I checked. When the glass is as dark as it needs to be to protect you, it's impossible to see through it to see what you're doing. Traditional visors require the user to leave it open, get ready the strike a spark, and then put the visor down right before. It's a pain in the ass, and if you're welding all day long, you're bound to accidentally strike a spark before the visor is down, leaving nice little trails on your eyes for awhile. With this, the initial spark is detected by a light sensor, and it auto darkens the glass. Much more convenient, especially when you need both of your hands to hold something in place before you start welding it.

I've always wanted something like this for the side windows in my car, and a nice little slider to adjust how dark they get. Alas, no one seems to make film I can apply. :(