Abstract
The major work in this thesis is to study the reaction time in the nanofluidic transistors system. The nanofluidic transistors can control the transport of cation in the nano-scale channel by changing the surface charge density on the wall of the nanochannel, which, in term, can be modified by a voltage applied on a nearly gate electrode. We utilize a unique design of the nanofluidic transistor, where the silicon gate electrode surrounds the nano-channel. The measurement of the gate effect of the electrical property confirms that the nanofluidic transistors can control the transport of cation. And the reaction time can be obtained by measuring the electrical current in the nanochannel while a square-wave gate voltage is applied. Our results showed that every time a sudden change in gate electrode potential would disturb the system and cause the changes of the current. We explained the consequence of disturbance with the conception of the gate effect. When our nanofluidic transistor was sited in the 0.001 M KCl solution, the magnitude of nanochannel was 38nm, and the gate electrode potential switched between 4V and -4V. The rate of current variation in nanochannel was 89.5％, and the reaction time of the system was 1s. In other words, when frequency of the applied square-wave gate electrode potential was less than 0.5 Hz, the nanofluidic transistor system could reach a steady state, and the electrical property satisfied the gate effect.