Sculpting a Mouse to Fit the User’s Hand

Let’s do a little experiment: hop onto your favorite search engine and try to find some decent in-ear monitor headphones. Now look at the requirements to place an order. You should see that they need to be custom-molded to fit your ears. That makes sense, because we all have different ears and it is important to get a comfortable fit with a good seal. But why don’t we do this with other devices? Our hands have just as much differentiation as our ears, which is why Ben decided to make his own mouse sculpted to his hand.

This isn’t a new idea, but it is something that manufacturers have never bothered to implement. They assume that most people will be happy enough with standard sizes. But anyone with a less typical hand size or shape is out of luck.

Ben has large hands and wanted an ergonomic mouse to suit them. So he sculpted (quite literally) a mouse design guaranteed to be perfect. He started with a big ol’ lump of clay and carefully molded it to his hand as it rested in a natural position. He then took several photos of his sculpture and fed those into photogrammetry software, which used them to create a 3D model. Ben was then able to use that as a reference in Autodesk Fusion 360 to create a parametric CAD model of the mouse enclosure.

With a perfect 3D-printable design ready to go, Ben needed some electronics. He ended up developing both wired and wireless versions. The wired version contains an Arduino Pro Micro, while the wireless version uses a FeatherS3 from Unexpected Maker. The later contains an ESP32-S3 microcontroller, which has a built-in Bluetooth adapter. Both versions take advantage of custom PCBs for the button, sensor, and scroll wheel connections. The buttons are Kailh low-profile mechanical key switches, the mouse sensor is an off-the-shelf generic model, and the scroll wheel is a rotary encoder.

After a few rounds of iteration to refine the designs, Ben had two mice that fit his hand like a tailored glove. The wireless version’s performance is subpar with some noticeable lag, thanks to programming complications. But Ben reports that the wired version works very well. And now he’ll never have to deal with an uncomfortable mouse again.