LG's new fingerprint sensor doesn't need a button.

LG Innotek has developed a fingerprint sensor that's placed under a glass surface instead of in a physical button, the company announced Sunday.

The new sensor could lead to smartphones that you can unlock by placing your finger on the phone screen. 

The LG-owned electronics parts manufacturer achieved this by cutting out a 0.01-inch thick slot in the lower part of a smartphone's cover glass, and then inserting a very thin fingerprint sensor into it. In other words, the sensor is still under the cover glass, but the slot moves the sensor close enough to the surface to read a fingerprint.

That way, the sensor is protected from water and scratches, and can be installed anywhere under the phone's glass surface. 

LG says the recognition accuracy of its module is comparable to that of a button-based fingerprint scanner. The probability of the sensor accepting the wrong fingerprint is 0.002%, the company claims. 

There's no word on when we'll see the new sensor installed into actual phones, but LG is already talking with potential customers.