Study on a Ring-shaped Interdigitated Electrode Controlled by AC Electrokinetic to Apply on Aquaculture for Rapid Bacteria Number Counting

• Main Authors: Sheng-KaiChung, 鐘聖凱
• Other Authors: Hsien-Chang Chang
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/x25b29

碩士 === 國立成功大學 === 生物醫學工程學系 === 102 === Generally, during the growth process of groupers, there are mainly three causative factors, including nervous necrosis virus, grouper iridovirus, Vibrio. According to reports and papers, nervous necrosis virus and grouper iridovirus can be detected with kits even micro-fluidic chips as fish fry timing. Despite this, it lacks relative devices to detect amount of Vibrio in pool. With compressed farming environment, remaining bait due to a large number of feeding, climate change, these unstable causative factors make groupers sick as amount of them reach certain value. Normally, as total bacterial concentration reaches 1x105 CFU/mL in pool, it makes groupers sick and dead, and leads to loss of aquaculture fisheries. As a result, to develop a device that can detect instant concentration of bacteria in pool is necessary. Based on electrodynamics, a micro-concentrator platform with Ring-shaped Interdigitated Electrode (RIDE) was designed, combined with micro electro mechanical systems (MEMS). Applying a certain AC voltage and frequency, without extra pumps, it can attract particles on insulating layer-modified RIDE which is lower electrical field. Then, AC electroosmotic (ACEO) transports particles to center of RIDE to be captured as images. Finally, bio-imaging software ImageJ is applied to analyze and quantify. In this research, the applied range of RIDE system improves from lab-made sample to real sample in the pool. From past result, it shows quantification of concentration in 10 min is achievable. Otherwise, pretreatment, chip design, experimental methods, image-analyzing are improved to increase accuracy. From result, with 100 L volume sample, RIDE system can detect concentration from 1x104 to 5x105 CFU/mL and the detecting time is shortened to be 20 min. Accuracy of the range can reach 83.33% under 10 times error. By developing this technology, not only aquaculture fisheries, it also can be applied to fields which have requirement in detecting instant concentration, such as bacteriuria, fermentation industry and food industry.