Hardware Reference
In-Depth Information
a
Contact region
Wire routing region
Contact pads
Electrode
Metal wire
Active region
b
CYTOP
Parylene C
1
st
Cr layer
Electrode
Ta
2
O
5
Aluminum
via
Al
Routing
wire
2
nd
Cr layer
SiO
2
Silicon substrate
c
Electrode
Via
Contact pad
Via
Routing wire
Active region
Wire routing region
Contact region
Fig. 7.1
(
a
) Layout of a biochip. The biochip has three regions: the region for fabricating
electrodes and on-chip reservoirs, the region for wire routing, and the region for fabricating
contact pads of input pins (Figure courtesy: Bang-Ning Hsu, Duke University); (
b
) side view
of the substrate and bottom layer for the two-metal-layer biochip [
6
,
7
]; (
c
) side view of the
interconnection between an electrode and its corresponding contact pad
In a cyberphysical microfluidic system, the control software may have to
dynamically adjust the schedules of fluidic operations as well as the routing paths
of droplets. Different bioassays can execute on the same biochip, general-purpose
pin-limited biochips [
3
,
4
] are good candidates as hardware platforms for low-cost
cyberphysical microfluidic systems.
However, despite the flexibility of general-purpose pin-limited biochips, the
routability of metal wires in such chip has remained an open problem until
now [
3
,
4
].
