Urinalysis is a common laboratory test used for diagnosis of a variety of systemic and genitourinary diseases. Although, collection of sample for urinalysis is extremely easy, when performed during an office visit, in pediatric and geriatric populations, who use diaper, such collection is not trivial and can result in missing important diagnostic information. For example, urinary tract infections (UTIs), are a major source of morbidity in incontinent elderly with dementia who cannot communicate their symptom to their caregivers. Although most UTIs are easily treatable with antibiotics, if not identified and treated timely, they can cause ascending infection, loss of kidney function, sepsis, and possible death. Deployment of smart, autonomous, diaper-embedded systems that can detect early signs of urinary dysfunction can have a significant impact on healthcare of our rapidly aging population. In this dissertation, I propose a diaper-embedded, low-cost, and disposable sensing platform comprising of a urine-activated battery and sensors for detection of nitrite (a surrogate for UTI), red blood cells (hematuria), and protein (proteinuria). I will first discuss my efforts to develop an optical/colorimetric nitrite sensor and a urine-activated power source, all fabricated on a hydrophobic paper/polymeric substrate through laser-assisted machining and lamination-assembly. The system stays in a dormant state until wetted by urine, after which the on-board power source is activated, awakening the rest of the measurement system (i.e., a light emitting diode, a photodetector, interface electronics, and a low-power Bluetooth module) and transmitting the presence or absence of nitrite in the urine to vicinal caregivers in a point-of-care and autonomous fashion. Thorough characterization of the performance and reliability analysis of the platform are also presented to envision its use as an end product. Afterwards, I will discuss the characterization of sensors, based on similar principle, for detecting red blood cells (hematuria) and protein (proteinuria), and the extendibility of the proposed platform for a multi-parameter system measuring nitrite, blood, and protein in the urine. Finally, I will conclude with other possible applications besides urinalysis for the proposed system.