Pakpum Somboon

Odor Recorder Capable of Wide Dynamic Recordable Range Based on Higher Order Sensing and Signal Extraction Technique for Small Signal

The odor recording method for extending dynamic recordable range was proposed. In this method, the enriched information obtained from higher order sensing based on preconcentrator with variable temperature was utilized so that the contribution of component with small ratio to sensor response could be separately extracted from that of the main component. Then, the signal extraction technique for small signal was developed using Savitzky-Golay filter for qualitative and quantitative detection of component with small ratio, and then this extracted information was used in recording process. It was found that the target odors including component with small ratio down to 1% were successfully recorded using this proposed method. This method is useful to extend the dynamic recordable range especially in the case that the component with high contribution in impression has low contribution to sensor responses.

Highly sensitive QCM odor-sensors functionalized with self-assembled lipid-derivatives and GC materials

We present a novel method for fabrication of highly sensitive quartz crystal microbalance (QCM) odor sensors using combined chemical- and physical sorption processes. In conventional techniques used for fabrication of the QCM sensors (e.g. spray-coating, atomizer) a bulky and costly setup is usually required. Here, we propose a simple method for functionalization of QCMs consisting in (i) chemisorption of a lipid-derivative(s) and then (ii) physical sorption of gas-chromatography (GC) stationary-phase materials from their ethanolic solutions. The materials self-organize on the sensor surface and the QCMs fabricated this way have sensitivity toward airborne odorants much higher than the sensors fabricated using conventional atomizer technique.

PEG Lipopolymers as Coatings for QCM Odor Sensors. Effect of Tether's Chain-length

Application of quartz crystal microbalance (QCM) sensors for odor sensing has been an important research topic. Proper performance of odor sensing systems with QCM sensors requires good discrimination among odor samples. Recently we have been studying pegylated lipopolymers -composed of lipid and poly(ethylene glycol). (PEG) The materials allowed for very good discrimination among odorants of different functional groups. Here we study lipopolymers with various molecular weight of PEG moiety. Our results indicate that the PEG chain length is an important factor influencing lipopolymers sensing properties.