Since locks were invented, locks have been playing an important role in people's daily life. Up to now, locks have two categories. One is mechanical lock and the other is electronic lock. The mechanical lock has simple structure and low cost. However, the mechanical lock has bad security and high interactive opening rates. In addition, one lock can only be opened by one key. Because of the development of modem micro-electronic technology, the electronic lock was invented on the basis of the mechanical lock. The electronic lock can increase the security of lock and the interactive opening rate has almost reduced to zero. In addition, one electronic card can open many locks of the same kind. However, current electronic lock cannot set the key itself, and it needs a desktop outside of the lock body to set the key. Therefore, the electronic lock is not applicable in fields where the desktop is not available (such as a family door) or where people could not use computer (such as people at countryside, children or elder people). Later, the fingerprint electronic lock was invented on the basis of the normal electronic lock. Though it is easy to open lock without a key, the fingerprint electronic lock is expensive, in large volume, and complicated in setting and resetting of fingerprints. In addition, both the normal electronic lock and the fingerprint lock need battery or power supply inside the lock, which can increase their volume. For such reasons, the electronic lock can only be used for doors, but not for drawers, cabinets, boxes, bags, transportation means, machinery, etc., where volume is limited. Moreover, the expiration time period of a battery is about 1 to 1.5 years. If the battery in the electronic lock has not been changed on time because of negligence, the lock may not be opened anymore and it will be unpleasant to pick the lock or break the door.
Conclusively, current existing locks including mechanical and electronic ones, or even fingerprint electronic locks, have so many disadvantages as mentioned above. In addition, they have no way to be simplified for one finger.