Design And Fabrication Of A Microchip To Generate Sequential Pulse Output For Artificial Skin Sensor Array

Abstract

In this project, we have designed and implemented the circuit, which basically generates sequential shifted pulse sequences. The circuit is a part of the pressure sensor system for colonoscopy. The other parts of the sensing system include the artificial skin sensor array and a data acquisition (DA) system. The circuit will be connected with sensor array to detect the signal at each dot of the sensing array grid. The artificial skin sensor array has been designed by our research partner in MIE department. The designed circuit will be integrated with the pressure sensor array to convert the pressure value into electrical signal, which should be readable from the computer terminal through a DA System. The designed circuit is expected to provide multiple outputs from a single input signal. Each output should be distinguishable. The work we reported in this thesis is the second version of the circuit design. The circuit designed in the first version has the problem of too much offset from our expected output. In this version, we improved this through adding additional noises and offset. We implemented the designed circuit on both breadboard and printed circuit board (PCB). Testing results on each board shows expected performance. In addition, we also made effort to fabricate the circuit on a microchip in order to minimize the size of the circuit and make it finally fit into the sensor system for practical application. We applied the very large scale integrated-circuit (VLSI) technique on the implementation of the microchip. We went through the procedure of creating the scheme of microchip fabrication through VLSI software Cadence® and verify the layout using Calibre® physical verification software. We used the free service from MOSIS, Inc for the fabrication process. The fabricated circuit is expected to arrive in a couple of months. Testing of the circuit will be one of our subsequent tasks of this project.