📍 Chicago, IL | 🔥 MicrosensorLabs | Flamesilk LLC | 🤖 Agentic builder of things that scratch the itch

"No problem is too small or too trivial if we can really do something about it." Just start building.

Healthcare sensor technology startup (NIH/NSF/DoD funded). I lead software across two product lines:

• 🔬 MagiCyte MB Imaging - Computer vision pipeline for identifying microbial colonies in imaged samples — Python, 1,400+ commits
• 🧫 MagiCyte SC Algorithm - Single-cell analysis algorithms with simulation and real-time MQTT processing — Python/Jupyter
• ⌚ Sanibit Wristband - BLE wearable firmware for hospital hand hygiene compliance — C/C++, 1,500+ commits
• 📡 Sanibit Controller - ESP32 & Dialog microcontroller firmware for dispensing detection and wristband communication — C, 1,900+ commits
• 🔧 Sanibit Tools - BLE debuggers, OTA firmware updater, and serial flashing utilities — C/Python

• 🧃AppJuice - a cross-platform AI app platform — a personal software factory where anyone can create, run, and share apps through natural language conversation, with no coding required.
• 📚 Tentix - Smart exam prep for Chicago Selective Enrollment & Academic Centers — AI-powered question bank with OCR scanning
• 🌐 Kinspace - Community platform for alterhuman identity exploration — messaging, profiles, AI-assisted content
• 🎰 OddChips - AI-powered apps platform with shared credit system
• 🖨️ HappyPrint - AI sticker generation meets print-on-demand — text prompt to physical stickers via Gelato
• 📖 VibeDict - Multilingual AI vocabulary notebook for macOS — definitions, translations & spaced repetition with Gemini
• 📕 I Can Read Chinese - Chinese leveled reading platform for kids and learners

• 🤖 SwiftAgentCore - Swift agent runtime with built-in tool execution, skill support, and a unified multi-provider LLM layer (OpenAI, Anthropic, Gemini, MiniMax, etc.)
• 🗂️ Mai - Native macOS Markdown library — A lightweight, pure-Swift alternative to Obsidian, powered by a native LLM agent (SwiftAgentCore) and tailored tools
• ☃️ Snowman - A standby home voice agent for Raspberry Pi with natural voice conversations (via OpenAI Realtime API or Gemini Live API), wake-word activation, local tools, and evolving memory
• 🐍 anything2md - Python package and CLI for converting documents (PDF, images, etc.) or URLs to Markdown via Cloudflare Workers AI
• 📝 Swift2MD - Lightweight Swift package and CLI for converting URLs or multiple-format documents into Markdown via Cloudflare Workers AI
• 🎙️ any-podcast - Make podcast from RSS, newsletters, and any URL. Deployed on Cloudflare workflow. Demo podcast
• 💬 anocus - Plug-and-play anonymous commenting system for static sites — Turnstile anti-bot, GitHub Discussions/KV storage, threaded replies
• 🤖 herrkaefer-skills - Agent Skills shared for improving coding efficiency and productivity with Claude Code and openAI codex. skills.sh
• 🦞 tinymolty - A easy setup, safe, low cost social agent for moltbook.
• 🎻 ziqi - Browser-based rhythm game for cello with real-time pitch detection — play online
• 🎙️ micpipe - macOS voice input via ChatGPT & Gemini — hold a key, speak, paste anywhere
• 🔈 SwiftEdgeTTS - Microsoft Edge text-to-speech in pure Swift
• 🔊 SwiftKokoroONNX - Pure Swift Kokoro TTS using local ONNX models
• 🗣️ vibe-narrator - Give your terminal agents a voice and a personality (Hugging Face MCP Hackathon project)
• 🤖 aspen-bot - Telegram bot for grade monitoring, built for Chicago Public Schools Parents
• 🧰 finder-toolbar-apps - Tiny macOS apps for your Finder toolbar — open in Cursor, iTerm, Sublime, and more
• 👶 face-fusion-stylegan2 - Predict what your kid might look like with StyleGAN2
• 🧹 cleanup-tabs - Chrome extension to close tabs in bulk by URL pattern

• 🧬 libevol - Evolutionary computation framework in pure C
• 🗺️ psycopgr - Python wrapper for pgRouting on real-world maps
• 🎨 sticker-genius - Generate sticker sheets with nano banana pro
• 📋 CaseAssistant - iOS ophthalmology case management app
• 📡 AccelerateWatch - FFT & FIR filters for watchOS, powered by Accelerate framework
• ✍️ chinese-calligraphy-vectorization - Vectorize Chinese calligraphy characters and generate custom copybooks
• 🚛 elastic-routing - Vehicle routing solver in C
• 🧭 travelling-planner - Optimal trip planning by solving TSP
• 🧠 nnet - Neural networks with back-propagation from scratch
• ⌚ MotionKit - Swift framework for accelerometer, gyroscope & magnetometer
• ⌚ WatchHapticSampler - Apple Watch haptic feedback demo
• 🐦 twitter2weibo - Repost tweets to Sina Weibo
• 👶 baby-naming - Interactive Chinese name selector for newborns
• 📄 markdown-to-pdf - Markdown to article/slide PDF with Chinese support
• 🚗 smooth-driving - Driving is playing! Challenge with others
• 🦴 c-project-and-python-wrapper-skeleton - Scalable C project skeleton with Python/Cython wrapper

• Building with coding agents - Claude Code, Cursor, and custom Skills are my daily drivers
• Building Flamesilk - Education and AI products for families and learners
• Building AI-native macOS tools - Voice input, local TTS, Markdown workflows
• Exploring MCP & local AI - Building MCP integrations and running models on-device in Swift
• Writing at herrkaefer.com - On building, home automation, and life in general
• Shooting with a Ricoh GR - Street photography when not at the keyboard

• Gaze independent brain-computer speller with covert visual search tasks — Clinical Neurophysiology, 2011 (111 citations)
• A novel task-oriented optimal design for P300-based brain-computer interfaces — Journal of Neural Engineering, 2014 (52 citations)
• System and method for improving compliance with hand hygiene and PPE protocols — US Patent 10,679,488, 2020 (62 citations)
• System and method for detecting hand hygiene compliance — US Patent 10,403,121, 2019 (42 citations)
• Implementing an Electronic Hand Hygiene System Improved Compliance in the ICU — American Journal of Infection Control, 2021 (14 citations)
• Effects of reminders from Sanibit electronic hand hygiene system on compliance — Journal of Hospital Infection, 2025

Full list on Google Scholar

• Published researcher in brain-computer interfaces & biomedical engineering
• Bilingual builder — code and docs in English and Chinese
• Photographs with a Ricoh GR IIIx (dreaming of a GR IV)
• Finds more peace in blogging, but have become more active on X recently
• Has a complex but honest relationship with AI as a collaborator
• Vibe coding with my daughter occasionally in Google AI Studio