A Dual-angle fiber dynamic light scattering system integrated with microfluidic chip for particle size measurement

•A new fiber dynamic light scattering particle size measurement system with a microfluidic chip is proposed. The microfluidic analysis function and the optical function are integrated into an on-chip device, making the system miniaturized, highly integrated, and simple in optical alignment.•The design of ultra-short scattering light path and ultra-small sample volume effectively reduce the influence of multiple scattering on the measurement of high-concentration solutions, enabling the system to accurately measure polystyrene particle solution with a concentration of up to 14 mg/ml, with a relative measurement error of less than 6%.•The system realizes dual-angle dynamic light scattering measurement. The experimental results show that compared with single-angle measurement, dual-angle measurement has higher measurement stability (standard deviation less than 2.2% of the standard size). Dynamic light scattering (DLS) is an effective tool for measuring the distribution of the size of particles. In this work, we design a novel integrated dual-angle DLS prototype which incorporates microfluidic chip and fiber optic probes to achieve measurement at high concentration and a small amount of sample consumption(30 μl). The experimental results show that for the suspension with concentrations up to 14 mg/ml, the instrument can achieve high accuracy (relative error less than 6%). Particle size prediction at a series of concentration is calibrated using linear regression model in machine learning. Furthermore, we firstly implement dual angle on-line measurement in the fiber DLS system with microfluidic chip. The experiment results show improved repeatability of dual-angle DLS when compared with single-angle DLS measurement.