Have you ever wondered what actually happens behind every click of your mouse?
The answer lies within a component no larger than a fingernail: the microswitch. It determines the button’s tactile feel, lifespan, and response speed. This article explores the technical principles and underlying logic of the four mainstream microswitch designs currently in use.
I. Traditional Mechanical Microswitches
Mechanical microswitches are the most common type today. When a button is pressed, external force acts on an internal metal leaf spring via a transmission element. Once energy accumulates to a critical point, the moving contact at the end of the spring rapidly connects with the stationary contact, sending an electrical signal to the computer; upon release, the spring resets, breaking the circuit.
This structure offers a well-established tactile feel and distinct feedback. By adjusting the spring material, contact pressure, and travel distance, manufacturers can create various tactile sensations—ranging from crisp and soft to firm.
However, physical contact imposes inherent limitations. Over prolonged use, metal contacts oxidize and wear down, and the spring suffers from fatigue; this is the root cause of the “double-click” issue that often plagues mice after a year or two of use. The lifespan of mechanical microswitches typically ranges from 5 million to 50 million clicks.
II. Optical Microswitches
Optical microswitches utilize optical components to create a light path; the movement of an obstruction element controls the interruption or connection of this path to trigger a click signal. Essentially, “light” replaces metal contacts for signal transmission.
They offer three key advantages: significantly extended lifespan (often reaching 100 million clicks); faster response times (optical signal transmission takes 0.2ms to 1ms, eliminating the need for debounce algorithms); and immunity to double-clicking, as they fundamentally avoid contact oxidation and wear.
Their limitations include: the retention of an internal metal spring to maintain tactile feel, meaning elasticity may change over time; a tactile feel that differs significantly from traditional microswitches in early models; and poor interchangeability—they are not standalone, easily replaceable switches, requiring specialized PCB designs.
III. Optical-Magnetic Microswitches
Optical-magnetic microswitches are a patented technology developed by Fuhlen, first introduced in the G90 model in 2016. While the name resembles that of optical microswitches, the structural design is fundamentally different.
The core structure consists of a permanent magnet, a spring, and a sealed optocoupler system. When pressed, the end of the spring moves away from the magnet, shifting the light-blocking component and altering the optical path; the optocoupler detects this change and converts it into an electrical signal. Upon release, the permanent magnet pulls the spring back to its original position.
This design combines “optical signal triggering” with “magnetic return.” By replacing metal contacts with optocouplers and using magnetic force instead of the spring-back action of metal reeds, it fundamentally eliminates the “double-click” issue caused by metal fatigue.
Advantages: Lifespan exceeding 50 million clicks; trigger response of approximately 5ms (about three times faster than traditional microswitches); eliminates “dead travel” (pre-travel); magnetic return is faster.
Limitations: The first-generation feel was very stiff, though later iterations were tuned to resemble the Omron 7N; loud click sound; poor compatibility, requiring redesigns of the key structure and PCBA.
IV. HITS Electromagnetic Microswitch
In 2026, Logitech debuted the HITS electromagnetic microswitch system on the GPW5 “Snow Leopard,” marking the world’s first mass-produced gaming mouse featuring electromagnetic microswitches.
It completely eliminates physical contact trigger points, instead recognizing clicks by detecting changes in coil induction signals caused by keycap displacement. A reed plate positioned beneath the button connects to a circular electromagnetic motor; pressing the button energizes the magnetic coil to generate electromagnetic induction, driving the motor to produce tactile feedback vibrations.
As it relies on inductive triggering rather than fixed physical travel, users can customize the trigger point via software. It supports 10 levels of trigger point adjustment, 5 levels for Rapid Trigger (RT) reset points, and 6 levels of tactile feedback adjustment.
Advantages: Significantly reduced latency—official testing shows a click latency of 10.8ms for the GPW5 compared to 44.7ms for traditional microswitches (a difference of ~34ms); adjustable trigger points and tactile feel; theoretically eliminates double-clicking; settings can be shared and imported.
Limitations: Requires an adjustment period; the feel is somewhat soft at lower tactile settings; weight management is challenging due to the inclusion of the electromagnetic motor and coil (the GPW5 achieved a weight of 61g). V. Comparison of Technical Approaches
Regarding triggering mechanisms: mechanical microswitches rely on the physical contact of metal reeds; optical microswitches rely on the interruption of a light path; opto-magnetic microswitches combine light-path interruption with magnetic attraction for resetting; and electromagnetic microswitches rely on electromagnetic induction, involving no physical contact.
Regarding lifespan: mechanical microswitches range from 5 million to 50 million clicks; optical microswitches last approximately 100 million clicks; opto-magnetic microswitches exceed 50 million clicks; and electromagnetic microswitches have a theoretically infinite lifespan.
Regarding response speed: mechanical microswitches take about 15ms; opto-magnetic microswitches take about 5ms; and electromagnetic microswitches are approximately 30ms faster than traditional types.
Regarding customization capabilities: mechanical and optical microswitches offer virtually none; opto-magnetic microswitches allow for some optimization; and electromagnetic microswitches support multi-dimensional adjustment.
Regarding compatibility: mechanical microswitches offer the greatest versatility; optical and opto-magnetic microswitches are incompatible with traditional pin layouts; and electromagnetic microswitches are limited to Logitech’s proprietary designs.
These four microswitch technologies represent a three-stage evolution: from mechanical to opto-electronic, and finally to electromagnetic. Mechanical microswitches are physical switches; optical microswitches serve as a hybrid transition between mechanical and opto-electronic systems; opto-magnetic microswitches represent an innovative combination of optics and magnetism; and electromagnetic microswitches constitute a fully electronic sensing system. These technologies do not merely represent simple iterations of one another; rather, each addresses challenges across different dimensions.
