- Daeken is reverse-engineering the FBI “DIY DNA synthesis” microfluidic chip (from diyhpl.us/~bryan/nucleic/fbi-diybio-dna-v1.pdf) and mapping out a low-cost replication workflow: outsource a chrome-on-glass photomask, spin-coat a test-grade silicon wafer with standard photoresist, expose/develop, acid-etch the wafer for variable channel depth, then cast PDMS on the resulting master.

- The group debated SU-8 vs. conventional photoresist: SU-8 is photo-patternable and gives uniform depth but is expensive and limited to ~100 µm thickness; standard resist plus wet etching is cheaper, allows arbitrary depth control, and yields a more durable master.

- Cost targets were enumerated: test-grade 100 mm Si wafers from universitywafer.com are “tens of dollars,” outsourced chrome masks run ~US $300 each, and the all-in price per design iteration is estimated at ≈ US $400—low enough for open-source replication.

- A DIY spin-coater design was proposed: instead of a commercial vacuum chuck, use double-sided tape and a roughened wafer backside to hold 100 mm wafers at 4000 rpm, with plans to publish build instructions for community replication.

- Discussion of mask-resolution options included 2400 dpi transparency films (≈ 10 µm features) versus commercial chrome masks (≤ 2 µm); optical reduction or higher-resolution laser services were suggested as future upgrades.

- Carbon3D’s “CLIP” continuous liquid-interface printer was dissected: users noted its oxygen-inhibited polymerization and DMD-based UV projector, but dismissed marketing claims of “true 3-D printing” as incremental SLA; the Science paper (doi:10.1126/science.aaa2397) was linked via paperbot.

- Texas Instruments’ $1450 “LC3000-PRO” DLP pico projector with 385–405 nm UV LED and 4000 Hz binary pattern rate was highlighted as an off-the-shelf component for high-speed structured-light lithography or 3-D scanning.

- ParahSailin proposed an Ig Nobel–worthy experiment to identify the human olfactory receptor responsible for the “bleach-like” smell of semen, hypothesizing accidental cross-reactivity with chlorine-derived odorants.

- kanzure circulated the lowRISC Google-Summer-of-Code 2015 ideas list (lowrisc.org) and a blacklist of predatory open-access publishers (scholarlyoa.com) as community resources.