Microchip analysis device for fixed Caenorhabditis elegans by tapered micro channel

We propose a microfluidic device to analyze the feature of Caenorhabditis elegans (C. elegans) from an electric property. In this device, we assessed the body size of C. elegans using the microchip in which a capacitance sensor was embedded. This device is mainly composed of two parts. One is a tapered micro channel. The tapered micro channel was used to immobilize C. elegans and directly measure the body size by an optical microscope. The other is a pair of electrode. The electrode is attached on the bottom of the tapered micro channel to measure the capacitance change. The capacitance change happens when C. elegans is placed in the gap between the electrodes. To measure the body size of C. elegans by capacitance change, the suspension with C. elegans was introduced from the inlet and then the solution was sucked through the tapered micro channel by negative pressure. When the suspension of C. elegans was sucked, the position of C. elegans was controlled in the tapered micro channel. The body size and the capacitance change of total 15 C. elegans were measured. The body size of C. elegans was measured by the digital optical microscope and the capacitance change was measured by the proposed microchip. By comparison with the result of two methods, we confirmed the capacitance change was related with the body size of C. elegans.