This Hair Accessory Can Act Like a Panic Button A high-tech hair clip promises personal security.

Entrepreneurs: Rachel Emanuele and husband Arthur founded First Sign Technologies, a Scottsdale, Ariz.-based line of safety products. The company is launching with a hair clip that contains a mechanism capable of detecting sudden movements that may indicate that an assault or attack is taking place.

"Aha" moment: One dark night, Emanuele had an uneasy feeling when she arrived home. "The lights were out, and it was pitch-black outside," she says. "I realized then that our home security system protected only our house, not me coming home alone and facing a potential intruder."

Use your head: The couple spent more than two years researching their idea for a wearable safety device before landing on the concept of a barrette that could remain concealed and operate automatically. "We chose to create a hair clip since the head is the most commonly injured area during a violent assault," Emanuele says. "You can hold it in your hand when you're walking in a parking garage, or wear it under a ponytail. The idea is that if you're in danger, there's no way you'd have time to get out your cell phone and reach your app. Your brain doesn't react as you think it would during a dangerous situation."