# US 9,751,083 B2 · Electronic module for real-time droplet-position sensing and driving in digital microfluidic system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,751,083 B2 - Document ID: US9751083B2 - Status: Granted - Kind: B2 - Application number: 14/680,671 - Filed: 2015-04-07 - Published: 2016-10-13 - Granted: 2017-09-05 - Earliest claimed: 2015-04-07 - Assignees: University of Macau - Applicants: University of Macau - Inventors: Jie Gao; Tianlan Chen; Cheng Dong; Yanwei Jia; Pui-In Mak; Mang-I Vai; Rui Paulo da Silva Martins - Web page: https://patentgrep.com/patent/US9751083B2 ## CPC - B01L 3/502792: {for moving individual droplets on a plate, e.g. by locally altering surface tension} - G01N 27/44704: {Details; Accessories} - G01N 27/44756: {Apparatus specially adapted therefor} - G01N 27/44791: {Microapparatus (sample containers with integrated microfluidic structures B01L3/5027)} - B01L 2200/143: Quality control, feedback systems - B01L 2300/025: Displaying results or values with integrated means - B01L 2300/0887: Laminated structure - B01L 2400/0427: Electrowetting - B01L: CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract 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. ## Claims ### Claim 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. ### Claim 2 (depends on 1) The digital microfluidic system of claim 1, wherein the device is an electrowetting-on-dielectric (EWOD) device. ### Claim 3 (depends on 2) 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. ### Claim 4 (depends on 2) 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. ### Claim 5 (depends on 1) The digital microfluidic system of claim 1, wherein the HV switches IC chip array is for connecting/disconnecting the actuation pulse to the electrodes. ### Claim 6 (depends on 1) The digital microfluidic system of claim 1, wherein the ring oscillator is for generating the capacitance-derived frequency signal. ### Claim 7 (depends on 1) The digital microfluidic system of claim 1, wherein the analog switches IC chip array is for connecting/disconnecting the electrodes to the ring oscillator. ### Claim 8 (depends on 1) 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. ### Claim 9 (depends on 1) The digital microfluidic system of claim 1, wherein the electrodes are coplanar. ### Claim 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. ### Claim 11 (depends on 10) The digital microfluidic system of claim 10, wherein the device is an electrowetting-on-dielectric (EWOD) device. ### Claim 12 (depends on 11) 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. ### Claim 13 (depends on 12) 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. ### Claim 14 (depends on 10) The digital microfluidic system of claim 10, wherein the electrodes are coplanar.