Biochips – fundamentals and applications - Electrochemical Sensors, Biosensors and Their Biomedical Applications - page 346

Addressing Y

Column decorder (Counter electrode)

X4

X3

X2

X1

Y1 Y2 Y3 Y4 Y5

R

Array
electrode

Counter
electrode

FIGURE 11.27 Schematic of x-y addressable electronic arrayed biochip.

be located by x-y denotes. The x-y addressable bioarray can signifi cantly reduce I/O
lines. Assuming an n n array, 2 n 2 switches are required to multiplex n 2 times with-

out addressing for detection of all spots. However, an x-y addressable array only needs
2 n switches to multiplexing n times for all measurements. This design can not only sig-
nifi cantly cut down the manufacturing cost for both biochip and instrument due to low
I/O lines, fewer switches and simple multiplexing, but also greatly reduce the assay
time that is particularly important in diagnostic applications.

11.4.2.2 Fabrication technology for silicon-based substrates
Most fabrication techniques for silicon-based biochips have their roots in the stand-
ard manufacturing methods developed for the semiconductor industry. Currently, four