2009 Fiscal Year Final Research Report

A Study of Bacteria Monitoring in Hydroponic Solution

Research Project

Project/Area Number	20780186
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Single-year Grants
Research Field	Agricultural information engineering
Research Institution	The University of Tokyo
Principal Investigator	SHUZO Masaki The University of Tokyo, 大学院・工学系研究科, 助教 (10456155)
Project Period (FY)	2008 – 2009
Keywords	生物環境情報 / MEMS / 誘電泳動
Research Abstract	Hydroponic culture has recently attracted much attention as a possible alternative to traditional soil-based agriculture because of its potential to labor saving and its stability in crop supply. In this soil-less culture, water mixed with nutrients circulates in plastic gutters where the plants grow under greenhouse conditions. However, the hydroponic configuration renders plant disease outbreaks uncontrollable. Therefore, in-line monitoring of the bacteria concentration in the hydroponic solution is required to prevent plant diseases from spreading. In this report, a bacteria concentration sensor based on dielectrophoresis (DEP) was development. The bacteria sensing mechanism consists of two steps : 1) AC voltage is applied to hydroponic solution in order to separate bacteria from other micro particles by DEP and 2) the sorted bacteria are counted and bacteria concentration is calculated from the counted number and the flow rate in the micro channel.