Reliable Emerging Electronics in Wearable and Implantable Healthcare Applications

Flexible electronics (FE) are enabling a new generation of wearable and implantable healthcare systems; however, ensuring reliable operation remains challenging due to process variability, mechanical deformation, and harsh physiological environments. In implantable settings, long-term exposure to bodily fluids and pressure variations accelerates device degradation, while strict constraints on power and integration make the use of batteries and active electronics undesirable. This work presents a cross-layer approach to reliability in flexible healthcare systems by combining passive implantable sensing with robust wearable electronics. At the circuit level, we introduce ReFlex-LDO, a gainboosted IGZO-TFT low-dropout regulator designed for capacitorlight operation and integrated with a structural delay-based built-in self-test (BIST) scheme, achieving ∼95% fault coverage with minimal overhead. For signal acquisition, we develop a hierarchical fault modeling and mitigation framework for IGZObased Flash ADCs, enabling up to 98% single-fault and 91% multi-fault coverage through targeted design enhancements. At the system level, we propose a passive RF-based sensing mechanism for monitoring fluid flow in implantable biomedical devices, eliminating the need for on-board power and improving long-term reliability. By pairing passive implantable sensing elements with flexible wearable processing units, the proposed approach enables continuous health monitoring while mitigating risks associated with device degradation in the body.