- The murgen open-source ultrasound project was found to have skipped custom probe development; participants argued that a universal, software-defined driver/receiver board should come first, since commercial probes (especially 2-D arrays) are expensive and FDA-locked.  
- A Google Doc and GitHub repo (https://docs.google.com/document/d/1xvLWDbp0x6z0Ft3AsfxjIsLUNsg5smkTcYb1g4WVo5U/edit, https://github.com/kelu124/murgen-dev-kit) were circulated as the current reference for the ultrasound effort.  
- DNA synthesis was described as chemistry-limited rather than engineering-limited; photo-labile nucleotides could replace piezo print heads with projector-based patterning, but sourcing or synthesizing those nucleotides is the real hurdle.  
- Discussion of “metalenses” (flat nanostructured optics) concluded that their focusing likely arises from a hybrid of diffraction, refraction, and reflection via sub-wavelength silicon “nanofins”; a quick prototype path—etch fins in Si and cast clear plastic impressions—was proposed.  
- Cheap 1 mW red laser pointers ($1 each) were weighed against white LEDs for microscope illumination; lasers win on spot brightness and monochromaticity, but LEDs can deliver higher total flux with proper heat-sinking.  
- X5R ceramic capacitors were identified as ferroelectric (BaTiO₃-based) and therefore piezoelectric, making them candidate ultrasound transducers; PZT (lead zirconate titanate) alternatives were also referenced.  
- A subway-ad-inspired calculation showed that a 13 MP cellphone sensor (≈3 µm pixel pitch) already functions as an 85× microscope; adding a simple 1 mm-to-4 mm lens could push magnification to 300×, and rolling-shutter readout could give sub-micron closed-loop positioning feedback for manipulators.  
- The “Attention Schema Theory” paper (http://journal.frontiersin.org/article/10.3389/fpsyg.2015.00500/full) was re-circulated as a mechanistic account of subjective awareness, previously cited in an NIH-linked review (PMC4010745).  
- Debate on neural-network architectures noted that CNNs map well to (non-recurrent) visual cortex, whereas RNNs are more general; whether auditory cortex structure justifies CNN-style convolution remains unclear.  
- Long-term nuclear-waste signage ideas included burying waste inside fast reactors, designing containers that appear to be “rock bottom,” and using universally frightening imagery (vomiting figures, tumors) instead of abstract warnings.