Before the invention of the electronic gas sensor in the 1920s, people relied on primitive and dangerous methods. These include canaries to detect low oxygen environments in mines, and flame lights to detect methane and oxygen levels. The replacement of these methods with electronic sensors has increased both the safety and reliability of gas detection. In addition, a wider variety of gases can be sensed and quantified. Despite these improvements, issues with sensors persist. Selectivity, the ability to differentiate between gases, proves a challenge, as do sensitivity to small gas concentration, repeat measurement stability, and cost. One possible way to compete with these challenges may be the carbon nanotube (CNT) transistor. …show more content…
The unit needed to be airtight, transparent, and mostly nonreactive to allow for a wide variety of allowed substances. In choosing the material, we had to take into account the gasses that would be used, along with material properties regarding UV light transmission. Acrylic was the decided upon material satisfying the testing needs. The height requirements were set first, due to height restrictions of the microprobe station. The width and length were determined based off the dimensions of the transistor wafer. After much consideration, it was decided to make the housing a drawer to assist with reusability, safety, and ease of use. The drawer height was initially designed to house a small heater underneath allowing future testing. The design was drawn on AutoCAD, as shown in Figure …show more content…
The holes seen on the drawer face are for the gas and electrical connections. There is an input and output connection for the gas on opposite box sides. The electrical system requires 5 connections; 3 to gate voltage, 1 to source voltage, 1 to drain voltage. The holes are designed for typical banana plug attachments, enabling ease of use. Inside the box, the banana plug would be connected via clip to the board. When the clip is attached to the wafer, it in turns clamps it down to the drawer. This method would apply to the drain and source voltage. To connect to the gate voltage, the thinner silicon oxide layer on the bottom of the wafer would be scratched off and a rough metal would be placed on the drawer surface allowing electrical connection. This metal would be soldered to a wire and connected to the banana plug attachment. These connections allow for easy use and