Line-scanning LAPS array for measurement of heavy metal ions with micro-lens array based on MEMS

A new line-scanning light addressable potentiometric sensor (LAPS) array which is sensitive to heavy metal ions is introduced in this paper, on which three kinds of solid thin film materials (sensitive to Fe3+, Pb2+ and Cr6+, respectively) are deposited by means of pulsed laser deposition (PLD) technique. In contrast to multi-light sources, the single beam laser has better consistency in wavelength. With micro-lens array based on micro-electromechanical systems (MEMS) technique, the single beam laser is separated into a line-array focused laser. Every focused laser is modulated separately to eight different frequencies by the optical chopper. This novel device can simultaneously detect several areas of the LAPS with the line-scanning method. A 3 × 3 LAPS array can be obtained by only three scans. On the basis of this an integrated subminiature electronic tongue has been developed and it is able to measure heavy metal ions in seawater and waste water.