Integrated reference electrode and fluid dispenser
An apparatus including an integrated reference electrode and a fluid dispenser is described. The reference electrode includes a body and a tip. The fluid dispenser at least partially surrounds the tip of the reference electrode and includes an inlet, a chamber, and an outlet. The fluid dispenser is configured to receive a fluid sample from the inlet to the chamber and form a droplet of the fluid sample through the outlet so that the droplet is in fluidic contact with the tip of the reference electrode and associated with a known potential determined by the reference electrode.
1 . An apparatus, comprising:
a reference electrode, comprising:
an electrode body,
a metal plug,
a filling solution, wherein the metal plug and the filling solution are disposed in the electrode body, and
a frit disposed in the electrode body, wherein sidewalls of the frit are in contact with the filling solution; and
a dispenser, comprising:
a chamber configured to hold a fluid sample,
an enclosure surrounding the chamber; and
an outlet configured to output a droplet of the fluid sample,
wherein the chamber surrounds the electrode body of the reference electrode,
wherein inner surfaces of the enclosure and outer surfaces of the electrode body are separated from each other by the chamber, and
wherein the droplet of the fluid sample is in fluidic contact with a tip of the reference electrode.
2 . The apparatus of claim 1 , wherein the reference electrode comprises a diaphragm or a membrane disposed within the tip of the reference electrode, and
wherein the diaphragm or the membrane provides conductivity between the filling solution and the droplet of the fluid sample.
3 . The apparatus of claim 1 , wherein an outer surface of the dispenser has a cross-sectional shape different from a cross-sectional shape of an inner surface of the dispenser.
4 . The apparatus of claim 1 , wherein an outer surface of the dispenser has an oval cross-sectional shape and an inner surface of the dispenser has a circular cross-sectional shape.
5 . The apparatus of claim 1 , wherein the outlet of the dispenser is coplanar with an outer surface of the tip of the reference electrode.
6 . The apparatus of claim 1 , wherein the dispenser comprises a control element configured to control an opening of an outlet of the dispenser.
7 . The apparatus of claim 1 , further comprising a cap disposed on a body of the reference electrode, wherein the cap is configured to support the metal plug within the body of the reference electrode.
8 . The apparatus of claim 1 , wherein the dispenser comprises an inlet tube coupled to the chamber.
9 . The apparatus of claim 1 , wherein top and bottom surfaces of the enclosure and the electrode body are coplanar.
10 . An apparatus, comprising:
a reference electrode comprising an electrode body and an electrode tip, wherein the electrode body comprises a metal plug and a filling solution; and
a dispenser comprising a dispenser body and a dispenser tip,
wherein the dispenser body comprises a chamber surrounding the electrode body,
wherein sidewalls of the dispenser body and sidewalls of the electrode body are separated from each other by the chamber,
wherein an outlet of the electrode tip is coupled to an inlet of the dispenser tip and is wider than an outlet of the dispenser tip, and
wherein the dispenser tip is configured to output a droplet of a fluid in the chamber.
11 . The apparatus of claim 10 , wherein the fluid in the dispenser tip is in fluidic contact with the electrode tip.
12 . The apparatus of claim 10 , wherein the electrode tip comprises a frit and the frit is in fluidic contact with the fluid in the dispenser tip.
13 . The apparatus of claim 10 , wherein the dispenser body has a cross-sectional shape different from a cross-sectional shape of the electrode body.
14 . The apparatus of claim 10 , wherein the dispenser body has a cylindrical shape and the dispenser tip has a conical shape.
15 . The apparatus of claim 10 , wherein the metal plug extends out of the electrode body.
16 . An apparatus, comprising:
a reference electrode, comprising:
an electrode tip; and
an electrode body, comprising:
a filling solution, and
a conductive plug disposed in the filling solution; and
a dispenser, comprising:
a dispenser body comprising a chamber surrounding the electrode body, wherein inner surfaces of the dispenser body and outer surfaces of the electrode body are separated from each other by the chamber, and wherein bottom surfaces of the dispenser body and the electrode body are coplanar; and
a dispenser tip disposed under the chamber, wherein an inlet of the dispenser tip is in contact with an outlet of the electrode tip.
17 . The apparatus of claim 16 , wherein the inlet of the dispenser tip is wider than the outlet of the electrode tip.
18 . The apparatus of claim 16 , wherein the reference electrode comprises a diaphragm or a membrane disposed in a tip of the reference electrode.
19 . The apparatus of claim 16 , wherein the chamber has a cross-sectional shape different from a cross-sectional shape of an outlet of the dispenser.
20 . The apparatus of claim 16 , wherein the dispenser has an oval cross-sectional shape and the electrode body has a circular cross-sectional shape.