Geometry
Top view (left) and isometric view (right) of the placed-and-routed chip. Rendered with OpenSCAD from the chip’s SCAD source, ethyl_reroute.scad. Click for high-resolution.
Download: PNG (top) · PNG (iso) · SCAD source ↓
Specifications
Assay
This chip is designed to measure urinary ethanol concentration via an enzymatic NAD-NADH assay. Alcohol dehydrogenase (ADH) catalyses the conversion of ethanol + NAD+ → acetaldehyde + NADH; the resulting NADH absorbs at 340 nm and the absorbance is proportional to the ethanol concentration in the sample.
Clinically and forensically, urinary ethanol detection supports alcohol biomarker monitoring and recent-exposure screening — urine alcohol persists somewhat longer than blood alcohol after the last drink, making it useful for follow-up testing.
The chemistry is adapted from the Beckman Coulter AU480 reagent kit BASOSR9K229 (Ethyl Alcohol). The chip combines the urine sample with two reagent streams at the volumetric ratios required by the assay protocol; the output channel collects the mixed product for off-chip spectrophotometric readout.
Files
- SCAD
ethyl_reroute.scad1.7 MBDownload - LEF
h.r.3.3_ethyl_pcells.lef1.8 KBDownload - CSV
pcell_out_scad204 BDownload - PNG
ethyl_iso_large.png88.1 KBDownload - PNG
ethyl_top_large.png18.1 KBDownload
ethyl_reroute.scad is the placed-and-routed 3D geometry — the main OpenSCAD source for this chip. h.r.3.3_ethyl_pcells.lef contains chip-specific cell abstracts. pcell_out_scad lists the parametric serpentine-channel variants this chip required (with L1 / L2 / turn count). The PNG renders are high-resolution versions of the views shown in the Geometry section above.
Papers
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Related methodology archetype
Goenner, B., Temple, S., Zapata, S., Wakeham, D., Snelgrove, A., Gaillardon, P.-E., Nordin, G. P., & Gale, B. K. (2025). An open source platform to automate the design, verification, and manufacture of 3D printed microfluidic devices. Scientific Reports, 15, 33077. DOI: 10.1038/s41598-025-15976-9
Applications
For research use only. Not for use in diagnostic procedures.
A design for urinary ethyl alcohol detection by an enzymatic NAD–NADH assay, the kind used for alcohol biomarker monitoring and recent-exposure screening. One of the urinalysis chip designs in the Gale Lab urinalysis chip family (Erica Francis).