Provided is a refrigerator. The refrigerator is characterized by enabling at least a part of a refrigerator door to be selectively transparent by a user's operation, such that the user sees through an inside of the refrigerator while the refrigerator door is closed.

Provided is a refrigerator. The refrigerator is characterized by enabling at least a part of a refrigerator door to be selectively transparent by a user's operation, such that the user sees through an inside of the refrigerator while the refrigerator door is closed.

A touch sensitive device including a front panel having a touch surface and a back surface opposite the touch surface. The touch sensitive device further includes one or more vibration transducers mounted to the back surface, and a controller electronically connected to the vibration transducer. The controller receives, from the vibration transducer, a vibration signal, extracts feature information corresponding to predetermined features from the vibration signal, determines, based on the feature information, that a touch occurred within a predefined area of the touch surface, and outputs a signal indicating that the touch occurred within the predefined area of the touch surface.

The present invention relates to a transducer device comprising: At least one dielectric electro-active membrane, an actuation element coupled with the at least one electro-active membrane so that the electro-active membrane is biased in at least one of its plane directions;
wherein the actuation element is provided with a mass so that when electrically excited a first resonance frequency is developed in a fundamental mode of a longitudinal oscillation of the actuation element and a second resonance frequency is developed in a fundamental mode of a transverse oscillation of the membrane, wherein the second resonance frequency is at least six times higher than the first resonance frequency.

Provided is a refrigerator. The refrigerator is characterized by enabling at least a part of a refrigerator door to be selectively transparent by a user's operation, such that the user sees through an inside of the refrigerator while the refrigerator door is closed.

Provided is a refrigerator. The refrigerator is characterized by enabling at least a part of a refrigerator door to be selectively transparent by a user's operation, such that the user sees through an inside of the refrigerator while the refrigerator door is closed.

Provided is a refrigerator. The refrigerator is characterized by enabling at least a part of a refrigerator door to be selectively transparent by a user's operation, such that the user sees through an inside of the refrigerator while the refrigerator door is closed.

Provided is a refrigerator. The refrigerator is characterized by enabling at least a part of a refrigerator door to be selectively transparent by a user's operation, such that the user sees through an inside of the refrigerator while the refrigerator door is closed.

Provided is a refrigerator. The refrigerator is characterized by enabling at least a part of a refrigerator door to be selectively transparent by a user's operation, such that the user sees through an inside of the refrigerator while the refrigerator door is closed.

A system includes a physical disturbance sensor, a transmitter and a signal receiver. The physical disturbance sensor is coupled to a first medium. The transmitter is configured to send a signal to the physical disturbance sensor. The first medium is coupled to a second medium by an adhesive interface. At least a portion of the adhesive interface is between the first medium and the second medium. The signal receiver is electrically connected to the physical disturbance sensor and configured to receive a received signal from the physical disturbance sensor. The received signal from the physical disturbance sensor is correlated with the signal in determining a measure of a physical disturbance to the second medium that causes a change in the adhesive interface.