Method and apparatus for measuring a surface charge distribution, method and apparatus for measuring an electrical property of entities in a liquid
AssigneeOxford University Innovation Limited
InventorMadhavi KRISHNAN
Life of this patent
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Abstract
Methods and apparatus for measuring a surface charge distribution and/or electrical properties of entities in a liquid are disclosed. In one arrangement, a liquid (2) is provided in contact with a target surface (4). The liquid (2) contains charged entities (6). A concentration of the charged entities (6) in a region between a probe member (8) contacting the liquid (2) and the target surface (4) is detected at each of a plurality of different positions on the target surface (4). A surface charge distribution on the target surface (4) is determined using the detected concentrations.
Claims25
A method of measuring a surface charge distribution, comprising:
- providing a liquid in contact with a target surface, the liquid containing charged entities;
- detecting a concentration of the charged entities in a region between a probe member contacting the liquid and the target surface at each of a plurality of different positions on the target surface;
- determining a surface charge distribution on the target surface using the detected concentrations.
The method of 1, wherein the charged entities are fluorescent.
A method of measuring an electrical property of entities in a liquid, comprising:
- providing a liquid containing target entities in a region delimited by channel walls facing into the liquid, wherein the channel walls define a plurality of test regions in which a distance between the channel walls is different;
- detecting concentrations of the target entities in the test regions;
- and
- determining an electrical property of the target entities using the detected concentrations.
The method of 10, wherein an external electrical potential is applied to either or both of the channel walls, or a surface charge spontaneously arises on either or both of the channel walls.
A method of measuring an electrical property of entities in a liquid, comprising:
- providing a liquid containing target entities in a region delimited by channel walls facing into the liquid, wherein at least one of the channel walls defines a plurality of nanoscale recesses acting as electrical potential wells with respect to the target entities, the distance between a base of a nanoscale recess and the channel wall facing the nanoscale recess being different for two or more of the nanoscale recesses;
- detecting residence times of the target entities in the electrical potential wells;
- and
- determining an electrical property of the target entities using the detected residence times.
An apparatus for measuring a surface charge distribution, comprising:
- a liquid handling apparatus configured to allow a liquid to be provided in contact with a target surface;
- a probe member;
- a detection system configured to detect a concentration of charged entities between the probe member and the target surface at each of a plurality of different positions on the target surface;
- and
- an analysis unit configured to determine a surface charge distribution on the target surface using the detected concentrations of the charged entities.
An apparatus for measuring an electrical property of entities in a liquid, comprising:
- a liquid handling apparatus configured to allow a liquid to be provided in a region delimited by channel walls facing into the liquid, wherein the channel walls define a plurality of test regions in which a distance between the channel walls is different;
- a detection system configured to detect concentrations of target entities in the test regions;
- and
- an analysis unit configured to determine an electrical property of the target entities using the detected concentrations.
An apparatus for measuring an electrical property of entities in a liquid, comprising:
- a liquid handling apparatus configured to allow a liquid to be provided in a region delimited by channel walls facing into the liquid, wherein at least one of the channel walls defines a plurality of nanoscale recesses acting as electrical potential wells with respect to the target entities, the distance between a base of a nanoscale recess and the channel wall facing the nanoscale recess being different for two or more of the nanoscale recesses;
- a detection system configured to detect residence times of the target entities in the electrical potential wells;
- and
- an analysis unit configured to determine an electrical property of the target entities using the detected residence times.
Dependencies are inferred from the claim text.