A hinge and an electronic device are provided according to the present application. The hinge includes a spindle, a spindle sleeve arranged with respect to the spindle, and a first material with a variable state arranged between the spindle and the spindle sleeve, and a torsion of the spindle is variable according to the variable state of the first material. The electronic device includes the hinge, a first body and a second body; and the first body and the second body are rotatably connected via the hinge.

A hinge including a first bracket, a second bracket, a shaft, a fixing element and a position limiting ring is provided. The first bracket includes a first hole and a protrusion protruding from edge of the first hole toward inside of the first hole. The second bracket includes a second hole. The shaft has a cylinder portion passing through the first hole, a fixing portion passing through the second hole, and a first position limiting structure encircling the shaft. The fixing element is disposed at ends of the cylinder portion to fix the shaft to the first bracket. The position limiting ring encircles the shaft and located between the first bracket and the first position limiting structure. The position limiting ring has a second position limiting structure and a recess, the second position limiting structure engages with the first position limiting structure, and the protrusion is located in the recess.

A variable resistance brake clutch facilitates a rotational coupling of electronic device components, and can include a rotatable shaft, a brake disposed proximate the rotatable shaft, and an actuator coupled to and configured to actuate the brake. The brake applies a braking force against a rotational motion of the shaft, and release of the brake results in low to no frictional resistance against the rotational motion. The braking force can be provided by default, and a capacitive touch sensor or other input component can allow a user to actuate the actuator manually to release the brake when desired. The release can be maintained as long as the sensor detects the touch event or other user input. A processor and solenoid can facilitate actuation by on a touch event, which sensor can be located at a back corner of a laptop upper component.