4×3 Matrix Membrane Keypad Module

The 4×3 Matrix Membrane Keypad Module is a compact, low-profile user-interface peripheral that provides 12 individual tactile input keys. Arranged in a telephone-style grid layout, it features numeric digits 0–9, along with the special character keys * (asterisk) and # (hash).

Instead of heavy mechanical switches, the module relies on a flexible, ultra-thin multi-layer polyester film printed with internal silver-conductive ink traces. A peeling self-adhesive tape backing allows developers to easily paste the keypad flat against any smooth chassis or control panel surface. It is widely used for prototyping secure digital locks, data input terminals, calculators, and access panels powered by microcontrollers like Arduino, Raspberry Pi, or ESP32