Wearable biosensors′ ability to measure continuous health parameters gives promise to healthcare with great potentials to advance precision medicine. The stability and balance within the human body are critical for organ systems′ normal functions. The imbalance of electrolytes may lead to several diseases such as hypertension, heart failure, and kidney diseases. Sweat electrolytes analysis, that is, the analysis of one of the noninvasively accessible biofluids, can provide important information about physiologically relevant quantities, and a combination of them can be employed for comprehensive studies. However, wearable biosensors′ large‐scale utilization for extensive population monitoring requires rapid, reliable, low‐cost, and high‐throughput integration of such platforms. Here, 3D‐printing technology is adapted to develop a novel, multiplex, low‐cost, and mechanically flexible all‐inclusive integrated wearable (AIIW) patch, which contains 3D‐printed flexible sensors along with flexible wearable‐microfluidic sample handling (WMFSH) units, integrated in a few hours. The AIIW patch is fully characterized, and its utility for noninvasive and continuous health monitoring is successfully demonstrated by simultaneous ex situ and in situ measuring of multiple electrolyte levels in sweat. This work is envisioned as another step toward enabling personalized health monitoring practices by implementing 3D‐printing technology in the easy and low‐cost development of customized integrated, flexible wearable biosensing platforms to monitor an individual's health parameters.

Physiological signals contain a wealth of personal health information which needs continuous monitoring for early detection of disease‐induced physiological irregularities and can be established as a potential approach to developing personalized healthcare devices. However, it is restricted by the lack of cost‐effective, precise, sensitive, and biocompatible flexible wearable sensors that are rapidly, reliably, and cost‐effectively are integratable. Here the work is reported on the development of novel, multimaterial, and multilayer all‐3D‐printed nanocomposite‐based (M2A3DNC) microengineered, flexible, hybrid, and soft wearable pressure sensors to record sensitive and multiple physiological signals for real‐time human health monitoring. By applying the intrinsic property of extrusion 3D printing, the conductive layers as well as the hemicylinder microstructure dielectric layer are directly 3D printed by optimizing the moving path of a nozzle, with air voids formation after assembling to enhance the compressibility of the active layer in our sensors. The microengineered sensors exhibit a very low detection limit, rapid response time, a repeatable and reproducible mechanical property with matching modulus with human skin (0.57–3.7 MPa) while offering intimate contact to the skin, excellent biocompatibility, and high mechanical compressibility in the active layer which leads to significantly high sensitivity. Thus, the proposed 3D printed cost‐effective M2A3DNC sensors pave a novel path to develop a highly compressible microstructured device with high sensitivity and low detection limit in a time‐effective manner with demonstrated application in real‐time health monitoring and envision further applicability in robotics tactile sensing interfaces.