Open-Source Sentient Skin Ghost Key Prototype End-to-End Build Guide: From Ordering Parts to Final Test Bed

This guide provides a complete, repeatable path to fabricate and test a working Sentient Skin Ghost Key
prototype — a 20 mm dermal vortex tattoo that uses the human body as its dielectric capacitor at 100 MHz.

The system demonstrates a true Non-Equilibrium Living Computational Bit (LCB): the resonant structure only functions while embedded in living tissue and automatically “dies” when removed. The guide includes a complete bill of materials, stencil CAD specifications, ESP32-S3 firmware, ballistic-gelatin phantom recipe, seven-day build timeline, formal quality assurance metrics, and safety notes. Total cost is approximately $320 USD (2026 prices). Designed for any maker lab or university bioelectronics group.