They are using ultrasonic sensors that continuously send sound pulses into the muscle tissue in the forearm. Unlike electrical impulses, sound waves are reflected by tissue.

Qualcomm unveiled its Sense ID 3D fingerprint scanner at Mobile World Congress in Barcelona. It is the first biometric sensor to use ultrasonic technology to capture sweat pores a finger.

On the other hand, the ultrasonic fingerprint sensors create detailed 3D images of your fingerprints. The former uses bright light to capture the fingerprint while the latter employs sound waves ...