HTGAA 2026: Individual Final Project Documentation S. epidermidis Stress-Sensing Skin Patch Version 1 — Core Design and Circuit Validation SECTION 1: ABSTRACT Chronic psychological stress is a major contributor to cardiovascular disease, metabolic dysfunction, and immune dysregulation, yet the tools available for monitoring physiological stress in real time remain either invasive, clinically constrained, or unable to provide continuous data outside a hospital setting. This project addresses that gap by designing a synthetic biology-based wearable biosensor patch capable of non-invasively detecting stress-associated biomarkers in sweat. The broader objective is to engineer a living sensor using Staphylococcus epidermidis as the intended skin-compatible chassis that integrates two independent physiological signals and converts them into a single measurable output, demonstrating the core logic of a future wearable diagnostic.