Hardware Reference
In-Depth Information
(3.a) E
1C
and E
2C
both are connected to Pin A (or Pin B): Without loss of
generality, we assume that both E
1C
and E
2C
are connected to Pin A. One
example can be found in Fig.
6.2
d. When Droplet 1 is moved in the direction
indicated by the arrow, the control voltages applied to Pins A, B, C, D, and E
should be set as “Low”, “High”, “Low”, “Low”, and “Low”, respectively. In
this case, the electrode under Droplet 2 is applied “Low” voltage, while one
of the non-diagonal electrodes (which is connected to Pin B) is applied “High”
voltage. Therefore, no matter where the scheduled movement direction points,
Droplet 2 has to be moved in the direction indicated by the arrow. In this case,
the unwanted movement of the droplet may occur. The number of all possible
concurrent movements for the droplet pair is 1
C
3
3
D
10. To avoid unwanted
movement of droplets that may be located on any two arbitrary positions of
the layout, the pin-assignment configurations discussed in this case should be
forbidden.
(3.b) Pin A connects to E
1C
and Pin B connects to E
2C
(or vice versa): Assume
Pin A is also connected to electrode E
2L
2
CEG
2
, and Pin B is also connected to
electrode E
1L
2
CEG
1
.ThenCEG
2L
denotes the control electrode group whose
central electrode is E
2L
.SinceE
2C
and E
2L
are two adjacent electrodes, we
find that E
2C
2
CEG
2L
. Therefore, CEG
1
and CEG
2L
share two pins and their
central electrodes are both controlled by Pin A. The pin-assignment configuration
for CEG
1
and CEG
2L
is the same as the configuration discussed in Case (3.a),
and may lead to the unwanted movement of a droplet. The pin-assignment
configurations discussed in this case should also be forbidden.
(3.c) Pin A and B are connected to neither E
1C
nor E
2C
: An example is shown
in Fig.
6.2
e. Assume that Droplet 1 and Droplet 2 are scheduled to move in the
directions indicated by the arrows. For the movement of Droplet 1, the control
voltages applied to Pins A, B, C, D, and E should be set as “Low”, “High”,
“Low”, “Low”, and “Low”, respectively. Similarly, for the movement of Droplet
2, the control voltages on Pins A, B, F, G, and H should be set as “High”, “Low”,
“Low”, “Low”, and “Low”, respectively. Therefore, the status of Pin A and Pin
B corresponding to the movements of Droplet 1 and Droplet 2 are different. To
avoid a conflict, Droplet 1 and Droplet 2 must be moved in different clock cycles.
Assume that Droplet 1 is moved first; a “High” voltage will be applied to Pin B.
In order to keep Droplet 2 stay at its current position, a “High” voltage will also
be applied to the electrode under Droplet 2. Therefore, for the pin-assignment
configuration discussed in this case, one droplet can be moved freely, while
the other droplet may have to stall on the current electrode. The number of all
possible concurrent movements for the droplet pair is 1
C
1
C
2
2
D
6.Note
that even though droplets will not undergo unwanted movement or splitting in
this case, the number of possible movements is relatively low. This shows that
the flexibility of droplet movement in this case is rather limited, hence we should
avoid such a pin-assignment configuration.
(3.d) Pin A is connected to E
1C
or E
2C
, and Pin B is neither connected to E
1C
nor E
2C
: Without loss of generality, we assume that Pin A is connected to E
1C
.
Figure
6.2
f shows an example. In this pin-assignment configuration, unwanted
