IFC Design Changelog
Summary of key architectural decisions taken between V1, V2, and the current V3 design.
Elimination of per-line pullback — instantaneous Y-junction at H1
Every sample-delivery line required a pullback step to transfer fluid from Layer 1 (manifold) into Layer 2 (chip channels). Flow had to stop between staging and injection — incompatible with clean transient kinetics and segmented-plug operation.
Y-junction geometry at H1 allows instantaneous flow shift from bypass to chip without stopping. Combined with the new reverse B→A cascade (OM-13), sample can be staged, redirected, and injected continuously.
Sharp concentration fronts at sensors (~0.2–0.5 s transit), supports air-gap-segmented plug trains, and makes fast kinetics (koff up to ~10⁰ s⁻¹) achievable.
Removal of the B/C Y-split
A Y-split routed inlet flow into Channels B and C in parallel. In practice the split was mixing-prone and could not reliably deliver 50/50 flow — resistance asymmetries and junction dispersion made parallel dual-sensor operation unreliable.
Y-split eliminated. Channels B and C are now addressed via separate waste-gate paths (V4 for B, V5 for C), giving clean single-channel routing. Parallel dual-stream operation is still available via V4-mode (RB on ChA, sample on ChB) — achieved through geometrically independent channels rather than a common-inlet split.
Reliable single-channel addressing of B and C, clean dual-stream mode, predictable cascade flow distribution.
V3 waste-gate repositioning — unlocking the reverse cascade
The V3-V6 waste-gate combination was placed such that V3 was functionally redundant with V6 under normal operation. The pair was effectively useless as configured.
V3 waste gate moved to the opposite side of the manifold (gating H2 → WASTE directly, independent of V6). Each hole now has its own dedicated waste gate. This change enables the reverse B→A cascade path (OM-13) — sample entering at H2 (V8.NC) can exit at V7 via the chip, because V3 no longer blocks the alternative exit route.
The unique reverse-cascade path — FR-011a [CRITICAL] — becomes available. Not achievable in V1/V2.
V1+V2 binary combo collapsed into a single 3-way valve (V2 → V3)
The V1 + V2 valve pair, operated together, was functionally equivalent to a 3-way valve — two binary valves achieving the same routing decision.
Replaced the V1+V2 binary combo with an actual 3-way valve. Simpler plumbing, fewer components, fewer failure modes, cleaner firmware logic.
Buffer can no longer individually hit Channel B or C alone — only through cascade. Accepted because individual sample injection at B (V8=NC + V4) and C (V8=NC + V5) is preserved, and buffer wash of B/C via full cascade is acceptable for typical use.
Right-side input detailed for multi-workflow compatibility (V2 → V3)
Sample-inlet side had a single-purpose port interface.
Added the AIR port and detailed the right-side input geometry. Interface is now triply-compatible: (a) direct well input at SAMPLE_SPOT, (b) manual injection into the pump input, (c) autosampler via multi-position sample presentation.
Cartridge drops into multiple user workflows without hardware reconfiguration — research bench, clinical autosampler, or manual prototype testing all use the same cartridge.