Linear fluidic cell trap device for single cell detection
View Patent ↗A sensing structure is provided and includes a tubular element through which a fluid is flowable along a single path, an array of sensors disposed along a length of the tubular element whereby the fluid is flowable through each of the sensors and sensing circuitry electrically connected with each of the sensors and configured to measure a reactance of each of the sensors and to determine whether any reactance is indicative of a presence of a biological cell in the fluid flowing through the corresponding sensors.
1 . A sensing structure, comprising: a channel through which a fluid is flowable along a single path, the channel being defined in insulator layers between top and bottom wafers such that the channel is encompassed at upper and lower sides thereof and at opposite lateral sides thereof by the insulator layers; an array of sensors disposed along a length of the channel whereby the fluid is flowable through each of the sensors; and sensing circuitry, which extends into the channel and which is electrically connected with each of the sensors, the sensing circuitry being configured to measure a reactance of each of the sensors and to determine whether any reactance is indicative of a presence of a biological cell in the fluid flowing through the corresponding sensors.
2 . The sensing structure according to claim 1 , wherein each sensors comprises opposed electrodes on opposite sides of the channel.
3 . The sensing structure according to claim 1 , wherein three or more sensors are disposed along the length of the channel.
4 . The sensing structure according to claim 1 , the sensors are arranged at uniform intervals along the length of the channel.
5 . The sensing structure according to claim 1 , wherein the sensing circuitry is configured to measure at least one of capacitances and inductances across the array of the sensors.
6 . The sensing structure according to claim 1 , wherein the sensing circuitry is configured to measure at least one of a capacitance and an inductance of each one of the sensors.
7 . The sensing structure according to claim 1 , wherein, for when the fluid has an absence of the biological cell and when the fluid has the biological cell, the sensing circuitry is controllable to obtain a dielectric constant of the fluid over a range of operating frequencies.
8 . The sensing structure according to claim 7 , wherein the array of the sensors and the sensing circuitry is calibrated by obtaining the dielectric constant of the fluid over the range of operating frequencies for when the fluid has only one type of the biological cell.
9 . A sensing structure, comprising:
a bottom wafer;
a top wafer;
insulator layers interposed between the bottom wafer and the top wafer and formed to define a channel, which is encompassed at upper and lower sides thereof and at opposite lateral sides thereof by the insulator layers, and along which fluid is flowable along a single path;
sensors disposed along a length of the channel whereby the fluid is flowable through each of the sensors; and
sensing circuitry, which extends into the channel and which is electrically connected with each of the sensors, the sensing circuitry being configured to measure at least one of capacitances and inductances of each of the sensors and to determine whether any of the at least one of the capacitances and the inductances indicate a presence of a biological cell in the fluid flowing through the corresponding sensors.
10 . The sensing structure according to claim 9 , wherein the sensors comprise reference sensors and sample sensors interleaved along the length of the channel.
11 . The sensing structure according to claim 10 , wherein each of the sensors comprises pairs of ground-signal-ground (GSG) electrodes on opposite sides of the channel.
12 . The sensing structure according to claim 10 , wherein the sensing circuitry comprises probes, each probe comprising:
a pad exposed to an exterior;
probe tips disposed in the channel and in electrical contact with corresponding ones of the reference sensors and the sample sensors; and
metallization that extends through the insulator layers between the pad and each of the probe tips.
13 . The sensing structure according to claim 12 , wherein the probe tips of each probe are disposed in electrical contact with adjacent ones of the reference sensors and the sample sensors.
14 . The sensing structure according to claim 12 , wherein pairs of probes have overlapping probe tips.
15 . A method of operating a sensing structure for sensing a biological cell in a fluid, the method comprising:
defining a channel in insulator layers between top and bottom wafers such that the channel is encompassed at upper and lower sides thereof and at opposite lateral sides thereof by the insulator layers;
arranging sensors in an array along the channel;
disposing probe tips in the channel and in electrical contact corresponding ones of the sensors;
extending metallization from the probe tips to pads exposed at an exterior of the insulator layers and the top and bottom wafers;
obtaining a baseline reactance of each of the sensors;
flowing the fluid through the sensors in the array and along the channel;
obtaining a testing reactance of each of the sensors during the flowing of the fluid; and
determining whether a difference between the baseline reactance and the testing reactance of each of the sensors exists and is indicative of a presence of the biological cell.
16 . The method according to claim 15 , wherein:
the obtaining of the baseline reactance and the obtaining of the testing reactance each comprise obtaining a capacitance of each of the sensors, and
the obtaining of the baseline reactance and the obtaining of the testing reactance each comprise obtaining an inductance of each of the sensors.
17 . The method according to claim 15 , further comprising calibrating the sensors over a range of operating frequencies.
18 . The method according to claim 15 , wherein the obtaining of the baseline reactance comprises:
obtaining a first reactance of each of the sensors in an empty condition; and
obtaining a second reactance of each of the sensors during a flowing of the fluid with an absence of the biological cell.
19 . The method according to claim 15 , wherein the obtaining of the testing reactance of each of the sensors comprises continuing the obtaining in an event of one or more of a statistically significant number of the biological cell is not detected, data analytics does not detect a sufficient number of detection and identification events and a judgment that neural network training is not complete.
20 . The method according to claim 15 , further comprising training neural network models to identify different types of the biological cell.