<p>➀ Researchers have developed a cost-effective optical detection method for microfluidic devices using Light Dependent Resistors (LDRs), which could revolutionize point-of-care diagnostics and lab-on-a-disc platforms by enabling real-time fluid tracking without bulky, expensive hardware.</p><p>➁ The study introduces an optimized setup that pairs inexpensive LDRs with LEDs, improving the precision of these sensors by integrating them with custom-designed waveguides to reduce signal noise and detect subtle changes in fluid dynamics.</p><p>➂ Experiments demonstrated the system's capability to track fluid positions, droplet counts, and assess RBC deformability, showing potential in medical diagnostics and monitoring two-phase fluid interfaces in resource-limited settings.</p>