Membraneless electrochemical cell and microfluidic device without pH constraint

1. An electrochemical cell, comprising:

(a) a first electrode,

(b) a second electrode,

(c) a first fluid, in contact with the first electrode, and

(d) a second fluid, in contact with the second electrode,

wherein the first fluid and the second fluid are in parallel laminar flow, and the first fluid enters the electrochemical cell with a pH different from the second fluid,

the cell is a galvanic cell,

the cell is a fuel cell,

the first fluid comprises a hydrocarbon, and

the first fluid has a pH of at least 7.5.

2. An electrochemical cell, comprising:

(a) a first electrode,

(b) a second electrode,

(c) a first fluid, in contact with the first electrode, and

(d) a second fluid, in contact with the second electrode,

wherein the first fluid and the second fluid are in parallel laminar flow, and the first fluid enters the electrochemical cell with a pH different from the second fluid,

the cell is a galvanic cell,

the cell is a fuel cell,

the first fluid comprises a hydrocarbon, and

the first fluid has a pH of at least 9.

3. An electrochemical cell, comprising:

(a) a first electrode,

(b) a second electrode,

(c) a first fluid, in contact with the first electrode, and

(d) a second fluid, in contact with the second electrode,

wherein the first fluid and the second fluid are in parallel laminar flow, and the first fluid enters the electrochemical cell with a pH different from the second fluid,

the cell is a galvanic cell,

the cell is a fuel cell, and

the electrochemical cell produces a precipitate.

4. A fuel cell, comprising:

(a) an anode,

(b) a cathode,

(c) an anodic fluid, in contact with the anode, and

(d) a cathodic fluid, in contact with the cathode,

wherein the anodic fluid and the cathodic fluid are in parallel laminar flow, and at least one of the anodic fluid and the cathodic fluid enters the fuel cell with a pH above 7.5, wherein fuel for the fuel cell comprises a hydrocarbon.

5. The electrochemical cell of claim 4 , wherein at least one of the anodic fluid and the cathodic fluid has a pH above 9.0.

6. The fuel cell of claim 4 , wherein the hydrocarbon is methanol, ethanol or formic acid.

7. The fuel cell of claim 4 , further comprising an enzyme in contact with the anode, the cathode, or both the anode and the cathode.

8. The fuel cell of claim 4 , wherein the fuel cell produces a precipitate.

9. A method of generating electricity, comprising:

flowing a first and second liquid through a channel in parallel laminar flow;

wherein the first fluid is in contact with a first electrode and the second liquid is in contact with a second electrode,

complementary half cell reactions take place at the first and the second electrodes, respectively, and

a precipitate is produced.

10. The electrochemical cell of claim 1 , wherein a difference in the pH of the first fluid and the pH of the second fluid is at least 0.1.

11. The electrochemical cell of claim 2 , wherein a difference in the pH of the first fluid and the pH of the second fluid is at least 0.1.

12. The electrochemical cell of claim 3 , wherein a difference in the pH of the first fluid and the pH of the second fluid is at least 0.1.

13. The electrochemical cell of claim 1 , wherein the first electrode is an anode and the second electrode is a cathode.

14. The electrochemical cell of claim 2 , wherein the first electrode is a an anode and the second electrode is a cathode.

15. The electrochemical cell of claim 3 , wherein the first electrode is a an anode and the second electrode is a cathode.

16. The electrochemical cell of claim 1 , wherein the hydrocarbon is methanol, ethanol or formic acid.

17. The electrochemical cell of claim 2 , wherein the hydrocarbon is methanol, ethanol, or formic acid.