Electronic module for real-time droplet-position sensing and driving in digital microfluidic system
According to one aspect of the present disclosure, a digital microfluidic system is provided. The digital microfluidic system includes a device, a control electronics, a field programmed gate array (FPGA), and a computer. The device includes a droplet on an electrode array, where the electrode array includes a plurality of electrodes. The control electronics connects to the device and provides an actuation pulse to the electrodes, where the control electronics generates a capacitance-derived frequency signal. The FPGA connects to the control electronics and collects the capacitance-derived frequency signal. The computer connects to the FPGA, the computer uses a frequency of the capacitance-derived frequency signal to calculate a precise droplet position and generates a duration voltage signal.
1. A digital microfluidic system, comprising:
a device including a droplet on an electrode array, wherein the electrode array includes a plurality of electrodes;
a control electronics connecting to the device and providing an actuation pulse to the electrodes, wherein the control electronics generates a capacitance-derived frequency signal;
a field programmed gate array (FPGA) connecting to the control electronics and collecting the capacitance-derived frequency signal; and
a computer connecting to the FPGA, the computer using a frequency of the capacitance-derived frequency signal to calculate a precise droplet position and generating a duration voltage signal;
wherein the control electronics includes a printed circuit board (PCB) having a high-voltage (HV) switches IC chip array, a blocking capacitance array, an analog switches IC chip array, and a ring oscillator.
2. The digital microfluidic system of claim 1 , wherein the device is an electrowetting-on-dielectric (EWOD) device.
3. The digital microfluidic system of claim 2 , wherein the EWOD device comprises:
a first plate;
a second plate facing the first plate; and
the droplet in between the first plate and the second plate;
wherein the electrode array is on the second plate.
4. The digital microfluidic system of claim 2 , wherein the EWOD device further comprises a gap between the first plate and the second plate, wherein the gap is in the range of 1 μm to 1000 μm.
5. The digital microfluidic system of claim 1 , wherein the HV switches IC chip array is for connecting/disconnecting the actuation pulse to the electrodes.
6. The digital microfluidic system of claim 1 , wherein the ring oscillator is for generating the capacitance-derived frequency signal.
7. The digital microfluidic system of claim 1 , wherein the analog switches IC chip array is for connecting/disconnecting the electrodes to the ring oscillator.
8. The digital microfluidic system of claim 1 , wherein the blocking capacitance array is for connecting electrodes to the analog switches array, and for blocking a HV signal from the actuation pulse to the analog switches array.
9. The digital microfluidic system of claim 1 , wherein the electrodes are coplanar.
10. A digital microfluidic system, comprising:
a device including a droplet and an electrode array, wherein the electrode array includes a first electrode and a second electrode;
a control electronics connecting to the device and providing a first pulse to the first electrode, wherein the control electronics generates a capacitance-derived frequency signal;
a field programmed gate array (FPGA) connecting to the control electronics, and collecting the capacitance-derived frequency signal; and
a computer connecting to the FPGA, the computer using a frequency of the capacitance-derived frequency signal to calculate a precise droplet position and generating a duration voltage signal;
wherein the control electronics conducts a control process according to the duration voltage signal, the control process including:
providing the first pulse to the first electrode for kicking off the droplet till a centroid of the droplet reaching a centroid of the first electrode; and
providing a second pulse to the second electrode when a leading edge of the droplet reaches the second electrode; and
wherein the control electronics includes a printed circuit board (PCB) having a high-voltage (HV) switches IC chip array, a blocking capacitance array, an analog switches IC chip array, and a ring oscillator.
11. The digital microfluidic system of claim 10 , wherein the device is an electrowetting-on-dielectric (EWOD) device.
12. The digital microfluidic system of claim 11 , wherein the EWOD device comprises:
a first plate;
a second plate facing the first plate; and
the droplet in between the first plate and the second plate;
wherein the electrode array is on the second plate.
13. The digital microfluidic system of claim 12 , wherein the EWOD device further comprises a gap between the first plate and the second plate, wherein the gap is in the range of 1 μm to 1000 μm.
14. The digital microfluidic system of claim 10 , wherein the electrodes are coplanar.