Bead Filter Bench

A scaled-up, 3D-printable model of the AxisMED bacteria capture device. Two printed grids stand in for the device's filter layers, and glass beads stand in for what they catch.

4.5 mm slots

Layer 1 coarse debris filter, ~2–5 µm

2 mm slots

Layer 2 capture membrane, 0.22–0.4 µm

6–8 mm beads

Lysed blood-cell debris and aggregates of different sizes

3 mm beads

Bacteria, held on top of Layer 2 for Gram staining

Using it

• Drag the model to tilt and turn it. Gravity stays pointing down, so the beads roll the way the real device would.
• A quick drag shakes it. Flipping it upside down sends beads back up toward the inlet, which is how you empty the real one.
• Upright turns it back. Scroll or pinch to zoom. Space pauses.

Model

The filter body and clear panel are exported straight from the Onshape design, including the slide-in groove and the side snap bumps. Beads collide with every triangle of the body; the panel's inner face is the front wall.

Physics: glass beads in water, with buoyancy-reduced gravity, liquid drag and the forces of a device being turned by hand. Beads that stop moving rest in place until something disturbs them.