Nanoparticle trapping and transport techniques
Approaches presented herein enable a device for trapping nanoparticles. More specifically, the device comprises a dielectric layer, an electrically insulating lid, a plurality of trapping electrodes, and electrical circuit connectors. The dielectric layer has an exposed surface, which is structured to form a set of recesses in the dielectric layer. The recesses are dimensioned so as to allow nanoparticles (e.g. biomolecules) to be trapped. The electrically insulating lid extends above the exposed surface of the dielectric layer. A flow path is defined between the lid and the exposed surface, such that a liquid can be introduced in the flow path. The trapping electrodes are arranged opposite the lid with respect to the exposed surface to face respective ones of the recesses. This arrangement defines pairs, such that each pair associates one of the trapping electrodes with a respective one of the recesses.
1 . A nanoparticle trapping device, comprising:
a dielectric layer comprising recesses in an exposed surface of the dielectric layer that are dimensioned to trap nanoparticles;
an electrically insulating lid above the exposed surface defining a flow path between the lid and the exposed surface;
a plurality of trapping electrodes arranged in a region under the dielectric layer, each trapping electrode aligned with and beneath a respective one of the recesses;
a pair of counter electrodes attached to the electrically insulating lid arranged on a peripheral region of the flow path outside the region, wherein, when viewed from a z-direction orthogonal to a plane of the region, the pair of counter electrodes are located outside of the region of the trapping electrodes; and
electrical circuit connectors connecting each of the plurality of trapping electrodes to an individually addressable voltage bias.
2 . The device according to claim 1 , wherein the device comprises at least three of the trapping electrodes and at least three respective ones of the recesses.
3 . The device according to claim 1 , wherein each counter electrode is arranged so as to be exposed in the flow path and thereby contacting a liquid introduced in the flow path, in operation of the device, and wherein the electrical circuit connectors comprise further connectors, wherein one of the further connectors connects to one of the pair of the counter electrodes, and another of the further connectors connects to the other of the pair of the counter electrodes.
4 . The device according to claim 1 , wherein the device further includes an insulating substrate arranged below the dielectric layer and opposite the exposed surface, wherein at least a subset of the electrical circuit connectors extend on a surface between the insulating substrate and the dielectric layer, and wherein each of the plurality of trapping electrodes is at an interface between the dielectric layer and the insulating substrate.
5 . The device according to claim 4 , wherein each of the plurality of trapping electrodes protrudes from the substrate and is at least partly integrated in the dielectric layer.
6 . The device according to claim 4 , wherein the dielectric layer comprises silicon oxynitride (SiON), and wherein one or each of the lid and the substrate comprises glass.
7 . The device according to claim 1 , wherein both the recesses and the plurality of trapping electrodes are arranged according to a bidimensional pattern in a plane substantially parallel to an average plane of the dielectric layer.
8 . The device according to claim 7 , wherein the recesses comprise distinct subsets of recesses, and wherein the plurality of trapping electrodes comprise distinct subsets of trapping electrodes arranged to face the distinct subsets of recesses.
9 . The device according to claim 1 , wherein a minimal distance between the insulating lid and the exposed surface of the dielectric layer is between 10 nm and 200 nm, and wherein the minimal distance is measured substantially perpendicularly to an average plane of the dielectric layer.
10 . The device according to claim 1 , wherein an average depth of the recesses is between 10 nm and 200 nm, wherein the average depth is measured substantially perpendicularly to an average plane of the dielectric layer, wherein an average radius of the recesses is between 100 nm and 500 nm, and wherein the average radius is measured substantially parallel to an average plane of the dielectric layer.
11 . The device according to claim 1 , wherein an average thickness of the dielectric layer is between 10 nm and 10 μm, and wherein the average thickness is measured substantially perpendicularly to an average plane of the dielectric layer.
12 . A nanoparticle trapping system, comprising:
a nanoparticle trapping device, comprising:
a dielectric layer comprising recesses in an exposed surface of the dielectric layer that are dimensioned to trap nanoparticles;
an electrically insulating lid above the exposed surface defining a flow path between the lid and the exposed surface;
a plurality of trapping electrodes arranged in a region under the dielectric layer, each trapping electrode aligned with and beneath a respective one of the recesses;
a pair of counter electrodes attached to the electrically insulating lid arranged on a peripheral region of the flow path outside the region, wherein, when viewed from a z-direction orthogonal to a plane of the region, the pair of counter electrodes are located outside of the region of the trapping electrodes; and
electrical circuit connectors connecting each of the plurality of trapping electrodes to an individually addressable voltage bias; and
a control unit connected to the electrical circuit connectors and to the pair of counter electrodes, wherein the control unit is configured to apply the voltage biases to selected pairs of i) one of the plurality of trapping electrodes and ii) one of the pair of counter electrodes.