In recent years, the use of nano-structures such as nano-crystal, nanotube and nanowire, in chemical and biological detection, has been gaining popularity due to their superior performances.
Nano-structure with a large surface area to volume ratio provides high sensitivity, thus permitting prominent detection. Among them, SiNW is a highly desirable nano-structure for an integrated system as it can be formed by taking the advantages of mature IC technology. IME researchers have developed CMOS compatible technology to form arrays of Si nanowires which are electrically addressable on an individual basis. The nanowires are fabricated by self-limiting oxidation process of Si beams patterned using conventional photolithography. Being CMOS compatible, the approach avoids post-synthesis alignment and assembly of SiNW. For effective application of nanowire arrays as sensors, the target molecules need to be efficiently delivered to the sensors. For this, micro fluidic channel with either direct lining or hydrodynamic focusing is integrated with the SiNW sensors.
A paper detailing the development of this CMOS-compatible SiNW sensor has been presented at the 10th International Conference on Miniaturized Systems for Chemistry and Life Sciences (μTAS2006), held in Tokyo on November 5 - 9, 2006.
Figure 1. Schematic diagram for efficiency sample delivery in SiNW sensor: (a) Direct lining for long SiNW sensor, and (b) Hydrodynamic focusing for short SiNW sensor.
Figure 2. Experimental observation. Sample molecules are directed towards SiNW sensor by Hydrodynamic focusing. |
