Apple Inc.
Display stack with integrated force input sensor

Abstract:

A force input sensor can include a strain-sensitive region disposed as a meandering electrical trace onto a structural or functional layer of a display stack. In particular, the meandering electrical trace can include one or more diversions from a linear path, each diversion configured to increase the length of the electrical trace. A diversion can form a loop to increase the inductance of the meandering electrical trace; the inductance of the meandering electrical trace can be correlated to length of the inductive trace which, in turn, can be correlated to strain experienced by the structural or functional layer.