50 µL / 500 µm reaction chamber — our footprint (Fluidic 842)

Internal geometry — X-ray

See-through internal view. Left: fluid footprint in plan, true scale (teal); ports show as the wider circles. Right: isometric of the internal void, vertical z exaggerated 3× for visibility. The exterior is an opaque solid block — this is what is inside it.

Download: PNG (x-ray)

Longitudinal section & exterior

Longitudinal y=0 section of 50 µL / 500 µm reaction chamber — our footprint (Fluidic 842): grey solid, white chamber, channels and bores

Exterior isometric render of 50 µL / 500 µm reaction chamber — our footprint (Fluidic 842) (opaque block with two top bores)

Longitudinal section at y=0 (left): grey = solid, white = fluid voids. Exterior isometric (right): the outside of the CAD model, drawn opaque. Click either for full resolution.

Download: PNG (section) · PNG (top) · PNG (iso)

Description

A single monolithic resin-SLA block with one 50 µL, 500 µm-deep stadium reaction chamber, two straight 0.5 mm feed channels on the same floor, and two Ø1.5 mm vertical access bores to the top surface. The vendor part is a sealed polymer body — this is a different monolithic construction that reproduces the chamber's fluidic spec only. Footprint 34.1686 × 9.3246 × 2.3 mm.

The footprint here is ours, not the vendor’s. microfluidic ChipShop publishes only the chamber volume (50 µL) and its depth (500 µm). Those two numbers are the functional specification of a reaction chamber and the model reproduces them exactly — the mesh measures 49.9888 µL, -0.022% from target. The shape is not on record. This stadium comes from an inverse-solve: area = volume ÷ depth = 100 mm², then a width chosen to hold the same stadium aspect ratio (L/w = 2.7146) as chamberchip_f584 — that is w = √(A/2.5) = 6.3246 mm, giving a chamber length of 17.1686 mm. The width is ours; only the volume and depth are the vendor’s. It will not fit a ChipShop holder and is not dimensionally interchangeable with the vendor part.

Verification

metric	value
Chamber volume — vendor target	50 µL
Chamber volume — measured on the model's mesh	49.9888 µL (-0.022% vs target)
Chamber depth — vendor	500 µm
Chamber area (volume ÷ depth)	100 mm²
Chamber stadium (L × w) — OUR design	17.1686 × 6.3246 mm OUR DESIGN
Stadium aspect ratio (L/w)	2.7146 — held from chamberchip_f584 so the family is geometrically similar
Footprint (L × W × H) — OUR design	34.1686 × 9.3246 × 2.3 mm OUR DESIGN
Chip watertight	True
Chip Euler number	0 — genus-1: one cavity, two vents
Void connected bodies	1 — chamber and both bores continuous
Min feature vs Phrozen 12K X (px_min = 500/19)	26.32 px
Min feature vs Phrozen 12K Y (px_min = 500/24)	20.83 px
Min feature vs BYU Nordin (px_min = 500/7.6)	65.79 px

All geometry checks run with trimesh (merged vertices) on the exported STLs. See the bundled README for the full method.

Cross-family consistency. This inverse-solve reproduces the vendor volume to -0.022% here, and to the same −0.022% on every other chamber in this family — f843 (2.5 µL), f750 (5 µL), f585 (10 µL), f559 (20 µL), f842 (50 µL) and the original f584 (20 µL). Agreement to three decimal places across a 20× volume range is the only cross-check available for parts the vendor describes by volume alone, and it shows the solve behaves identically at every scale.

Source & print adaptation

Chamber (source → ours): 0.50 mm deep — as published; no print enlargement applied
Chamber volume: 50.0 µL published / 49.9888 µL in the model (mesh)
Target printer: Phrozen Sonic Mighty 12K — 19 µm (X) × 24 µm (Y), non-square
Source: microfluidic ChipShop — Fluidic 842 (vendor product page)

Source dimensions are what the originating design publishes; ours are what our CAD model is drawn at. Where the two are the same number, no feature was resized to print. No public URL for the source is on record in this repository, so it is cited as plain text rather than linked.

Provenance & caveats

Vendor-attributed: chamber volume (50 µL) and chamber depth (500 µm) — product page. Nothing else. OURS (not the vendor’s): the chamber shape, the whole footprint, the feed-channel geometry and the port style. Ports are simplified straight cylindrical bores, standing in for the vendor’s MFCS Mini Luer sockets. Printability: px_min = 26.32 px in X and 20.83 px in Y on the Phrozen Sonic Mighty 12K (19 × 24 µm), and 65.79 px on the BYU Nordin printer (7.6 µm/px). These are pixel counts; for the process limits on record for each printer, see Hardware and process. Status — Phrozen Sonic Mighty 12K design, checked in CAD: the geometry is watertight and volumetrically checked in CAD — see the Verification table above.

Files to download

SCADchamberchip_f842.scad12.5 KBDownload
STLchamberchip_f842.stl208.9 KBDownload
STLvoid_chamberchip_f842.stl206.0 KBDownloadFor inspection, not for printing: the fluid network, every space that holds liquid, as a solid.
PNGchamberchip_f842_xray.png170.3 KBDownload
PNGchamberchip_f842_section.png23.3 KBDownload
MDREADME.md1.7 KBDownload