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What is a Computer mouse made of?

What is a Computer mouse made of?
An ABS shell around a tiny camera taking thousands of pictures a second, plus two clicky microswitches and PTFE feet.

The optical mouse replaced the ball mouse in the late 1990s because it removed the only moving parts that touched the desk, and with them the ritual of scraping fluff off the rollers. What it introduced was surface dependence: an optical sensor needs texture to track, so glass and plain gloss surfaces defeat it unless the mouse uses a laser or a dedicated glass-tracking sensor. The double-click fault that afflicts so many mice is a switch problem rather than a software one — contact bounce grows as the leaf spring fatigues, and the fix is replacing an inexpensive switch, which is why it is such a common repair.

Component by component

Every material is a choice, and the third column is the constraint that drove it.
Part Material Why that material
sensor a CMOS image sensor with an infrared or red LED, or a laser It photographs the surface thousands of times a second and computes how the image shifted — a mouse is a very small camera.
buttons mechanical microswitches with a metal leaf contact The leaf gives the tactile click and the rating, and it is where the notorious double-click fault develops as the metal fatigues and oxidises.
scroll wheel a slotted wheel over an optical or mechanical encoder, with a rubber tyre The encoder converts rotation into pulses; a mechanical one wears and starts scrolling the wrong way intermittently.
feet PTFE skates PTFE has about the lowest friction of any solid, so the mouse glides on a few square millimetres of contact.
shell ABS, sometimes with a rubberised coating Rubberised coatings feel good new and go sticky as the polyurethane hydrolyses, which is why they have fallen out of favour.

Other electronics objects

Common questions

What is a Computer mouse made of?
An ABS shell around a tiny camera taking thousands of pictures a second, plus two clicky microswitches and PTFE feet.
What is the sensor of a Computer mouse made of?
A CMOS image sensor with an infrared or red LED, or a laser. It photographs the surface thousands of times a second and computes how the image shifted — a mouse is a very small camera.
What is the buttons of a Computer mouse made of?
Mechanical microswitches with a metal leaf contact. The leaf gives the tactile click and the rating, and it is where the notorious double-click fault develops as the metal fatigues and oxidises.

Related pages

Sources

  1. Typical range compiled from manufacturer specifications — At One Place

How these figures are compiled and checked