การสร้างอุปกรณ์ชิปของไหลจุลภาคแบบพกพาสำหรับตรวจวัดความผิดปกติในน้ำนมวัว

Abstract

In modern dairy farming, after obtaining raw cow's milk from dairy cows, it is essential to test the raw milk before processing it into dairy products. The quality of raw milk directly influences the quality of the final dairy products. To ensure that dairy products meet consumption standards, raw milk quality testing is a critical focus for the dairy industry. The quality of raw milk also determines its purchasing price. High-quality and substantial quantities of raw milk contribute to increased value and higher prices. Quality testing of raw milk serves several purposes: determining the raw milk’s price, grading its quality, and ensuring that low-quality milk does not mix with high-quality milk. It also detects mastitis in cows, a prevalent issue caused mainly by bacterial infections, particularly Staphylococcus spp. and Streptococcus spp. Mastitis not only affects the quantity and quality of raw milk but is also one of the most common diseases in the dairy industry. This research utilizes a microfluidic system for testing due to its portability, accuracy, and speed. The researchers have designed and developed a portable microfluidic system to detect abnormalities in cow’s milk, aiming to create a microfluidic chip that can be applied for milk abnormality detection. The microfluidic system structure selected for this research is the Spiral-microchannel based on Dean's principle. The optimal structure was determined considering four factors: width, height, number of spiral loops, and flow rate. The experiments conducted followed the Design of Experiments (DOE) methodology. Results indicate that the most effective microfluidic chip for somatic cell separation had a width of 250 micrometers, a height of 100 micrometers, 10 spiral loops, and a flow rate of 0.4 milliliters per minute. The efficiency equation derived is as follows: Efficiency = 1.092 − 0.00697A − 0.00515B − 0.0588C + 0.933D + 0.000045AB + 0.000535AC − 0.00411AD + 0.0079CtPt The maximum efficiency calculated for the microfluidic chip is 0.697, with a Reynolds number of 29.80 and an average Dean number of 3.15. For abnormality detection using the microfluidic chip, the study analyzed abnormalities in raw milk by measuring somatic cell counts at both the Inner Wall Outlet and Outer Wall Outlet. This differentiation helps distinguish between normal and abnormal milk samples using the developed microfluidic chip. The researchers established a threshold ratio of 1.8, which effectively differentiates and identifies abnormalities in raw milk samples with high efficiency. The sensitivity and specificity calculated for this threshold are 0.90 and 0.80, respectively. Using the threshold ratio of 1.8 to identify abnormalities in raw milk samples achieves an accuracy of 0.87 or 87%.