What is a mouse made of? - briefly
A computer mouse is built from a molded plastic shell that encloses a printed circuit board, a microcontroller, an optical or laser sensor, and button mechanisms with springs. Power comes from AA/AAA batteries or a USB connection.
What is a mouse made of? - in detail
A computer mouse consists of an outer shell, internal electronics, a motion‑detecting sensor, a scrolling mechanism, input switches, and a power source.
The shell is typically injection‑molded from thermoplastic polymers such as ABS (acrylonitrile‑butadiene‑styrene) or polycarbonate. These materials provide durability, impact resistance, and the ability to be textured with rubberized or silicone grips for comfort. In premium models, the housing may incorporate aluminum or magnesium alloy frames to increase rigidity and give a metallic finish.
Inside the shell lies a printed circuit board (PCB) fabricated from FR‑4 fiberglass laminate. The PCB carries copper traces that connect the microcontroller, sensor, and input components. The microcontroller is a silicon‑based integrated circuit that processes button signals, scroll‑wheel data, and sensor output, then communicates with the host computer via USB or a wireless protocol.
Motion detection relies on either an optical sensor (LED‑illuminated) or a laser sensor. The LED element is a gallium‑arsenide (GaAs) or gallium‑nitride (GaN) diode, while the laser module uses a semiconductor laser diode. Both emit light onto the surface beneath the mouse; a tiny image sensor captures reflected light and translates it into movement data.
The scroll wheel is a small, hollow cylinder made of plastic or metal, equipped with a rotary encoder that generates incremental pulses as the wheel turns. Left‑ and right‑click buttons employ mechanical microswitches, usually consisting of a plastic housing, a metal contact leaf, and a spring that returns the switch to its default position.
Power is supplied by a cable or a wireless battery. Wired models use a copper‑clad cable terminated with a USB connector. Wireless versions contain a rechargeable lithium‑ion cell or a disposable AA/AAA alkaline cell, together with a radio‑frequency (2.4 GHz) or Bluetooth transceiver module.
A typical assembly sequence includes: molding the shell components; mounting the PCB and attaching the sensor, microcontroller, and switches; inserting the scroll wheel and battery (if present); routing the cable; and sealing the halves of the shell with screws or snap‑fit clips.
Overall, the mouse combines polymer housings, metal contacts, semiconductor chips, optical components, and electrical interconnects to deliver precise cursor control.