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The electronic tongue is an instrument that measures and compares tastes. It was invented by Professor Fredrik Winquist of Linköping University, Sweden. Chemical compounds responsible for taste are detected by human taste receptors, and the seven sensors of electronic instruments detect the same dissolved organic and inorganic compounds. Like human receptors, each sensor has a spectrum of reactions different from the other. The information given by each sensor is complementary and the combination of all sensors' results generates a unique fingerprint. Most of the detection thresholds of sensors are similar to or better than those of human receptors. In the biological mechanism, taste signals are transducted by nerves in the brain into electric signals. E-tongue sensors process is similar: they generate electric signals as potentiometric variations. Taste quality perception and recognition is based on building or recognition of activated sensory nerve patterns by the brain and on the taste fingerprint of the product. This step is achieved by the e-tongue’s statistical software which interprets the sensor data into taste patterns. == Operation == Liquid samples are directly analyzed without any preparation, whereas solids require a preliminary dissolution before measurement. Reference electrode and sensors are dipped in a beaker containing a test solution. A voltage is applied between each sensor and a reference electrode, and a measurable current response results that is consistent with the Cottrell equation. This current response is a result of oxidizing reactions that take place in the solution due to the voltage difference, and can be amplified through catalytic surface treatments. The response is measured and recorded by the e-tongue's software. These data represent the input for mathematical treatment that will deliver results. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Electronic tongue」の詳細全文を読む スポンサード リンク
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