Variable potential electrokinetic device

• US 6,719,535 B2
• Filed: 01/31/2002
• Issued: 04/13/2004
• Est. Priority Date: 01/31/2002
• Status: Expired due to Fees

• Current Assignee: Teleflex Life Sciences Pte., Ltd. (Teleflex Incorporated)
• Original Assignee: Eksigent Technologies LLC
• Inventors: Neyer, David W., Rakestraw, David J.
• Primary Examiner(s): Yu, Justine R.
• Assistant Examiner(s): Solak, Timothy P.
• Application Number:
  US10/066,528
• Publication Number:
  US 20030143081A1
• Time in Patent Office: 803 Days
• Field of Search: 417/49, 417/48, 417/50, 417/53
• US Class Current: 417/50
• CPC Class Codes: F04B 17/00 Pumps characterised by combination with, or adaptation to, specific driving engines or motors
• CPC Class Codes: F04B 19/006 Micropumps F04B43/043 and F04B43/095 take precedence
• CPC Class Codes: Y10S 977/70 Nanostructure
• CPC Class Codes: Y10S 977/932 for electronic or optoelectronic application

Abstract

Variable potential electrokinetic devices and electrokinetic multipliers used for pumping and flow control are disclosed that offer improvements in safety and design flexibility. The devices of the present invention take advantage of combinations of pumping conduits and conducting conduits to permit the use of lower operating voltages in pumps, pressure multipliers, and flow controllers. Devices having N pumping stages and 2N+1 electrodes permit the use of arbitrary voltages at the fluid connection points between the devices and other system components, further improving device safety and flexibility.

Claims

1. An electrokinetic device, comprising:

a pumping conduit having a first end and a second end, and including a porous dielectric material;

a conducting conduit having a first end and a second end, said pumping conduit second end and said conducting conduit first end connecting at a junction; and

at least one electrode in electrical communication with said pumping conduit and said conducting conduit, the total number of electrodes being odd.

2. The electrokinetic device of claim 1, wherein said odd number of electrodes comprises a first electrode at potential V1 in electrical communication with said pumping conduit first end, a second electrode at potential V2 in electrical communication with said pumping conduit second end, and a third electrode at potential V3 in electrical communication with said conducting conduit second end, and wherein V1 does not equal V2.

3. The electrokinetic device of claim 2, wherein V3 does not equal V2.

4. The electrokinetic device of claim 2, wherein V1, V2, and V3 are selected so that (V2−

V1) and (V3−

V2) are oppositely signed.

5. The electrokinetic device of claim 4, wherein V1 is equal to V3.

6. The electrokinetic device of claim 5, wherein said potentials V1 and V3 are ground potentials.

7. The electrokinetic device of claim 1, wherein said conducting conduit includes a porous material.

8. The electrokinetic device of claim 1, wherein said conducting conduit hydrodynamic conductance, k_c, is greater than said pumping conduit hydrodynamic conductance, k_p.

9. The electrokinetic device of claim 8, wherein k_c/k_p≧

2.

10. The electrokinetic device of claim 9, wherein k_c/k_p≧

10.

11. The electrokinetic device of claim 10, wherein k_c/k_p≧

100.

12. The electrokinetic device of claim 11, wherein k_c/k_p≧

1000.

13. The electrokinetic device of claim 12, wherein k_c/k_p≧

10,000.

14. The electrokinetic device of claim 1, wherein said conducting conduit electrokinetic pressure value, p^ek_c, is less than said pumping conduit electrokinetic pressure value, p^ek_p.

15. The electrokinetic device of claim 14, wherein p^ek_c/p^ek_p≦

0.5.

16. The electrokinetic device of claim 15, wherein p^ek_c/p^ek_p≦

0.1.

17. The electrokinetic device of claim 16, wherein p^ek_c/p^ek_p≦

0.01.

18. The electrokinetic device of claim 17, wherein p^ek_c/p^ek_p≦

0.001.

19. The electrokinetic device of claim 18, wherein p^ek_c/p^ek_p≦

0.0001.

20. The electrokinetic device of claim 1, wherein said conducting conduit electrical resistance, R_c, is greater than or equal to said pumping conduit electrical resistance, R_p.

21. The electrokinetic device of claim 20, wherein R_c/R_p≧

2.

22. The electrokinetic device of claim 21, wherein R_c/R_p≧

5.

23. The electrokinetic device of claim 22, wherein R_c/R_p≧

10.

24. The electrokinetic device of claim 23, wherein R_c/R_p≧

100.

25. The electrokinetic device of claim 1, wherein said device is capable of generating 0.1 psi/volt applied across said pumping conduit.

26. The electrokinetic device of claim 25, wherein said device is capable of generating 1 psi/volt applied across said pumping conduit.

27. The electrokinetic device of claim 26, wherein said device is capable of generating 10 psi/volt applied across said pumping conduit.

28. A method of controlling the flow of a fluid, comprising:

contacting said pumping conduit first end of the electrokinetic device of claim 1 with a fluid; and

supplying potential V1 to a first electrode in electrical communication with said pumping conduit first end, potential V2 to a second electrode in electrical communication with said junction, and potential V3 to a third electrode in electrical communication with said conducting conduit second end.

29. The method of claim 28, wherein V1 does not equal V2.

30. The method of claim 28, wherein V3 does not equal V2.

31. The method of claim 28, wherein V1, V2, and V3 are selected so that (V2−

V1) and (V3−

V2) are oppositely signed.

32. The method of claim 28, wherein V1 is equal to V3.

33. The method of claim 32, wherein said potentials V1 and V3 are ground potentials.

34. The method of claim 28, further comprising supplying a pressure-driven flow to said pumping conduit, and modulating said pressure-driven flow by an electroosmotically-driven flow component generated within said pumping conduit.

35. An electrokinetic device, comprising:

a first pumping conduit having a first end and a second end, and including a first porous dielectric material;

a first conducting conduit having a first end and a second end, said first pumping conduit second end and said first conducting conduit first end connecting at a first junction;

a second pumping conduit having a first end and a second end, and including a second porous dielectric material, said first conducting conduit second end and said second pumping conduit first end connecting at a second junction; and

a first electrode in electrical communication with said first pumping conduit first end, a second electrode in electrical communication with said first junction, a third electrode in electrical communication with said second junction, and a fourth electrode in electrical communication with said second pumping conduit second end,

wherein said conducting conduit electrokinetic pressure value, p^ek_c, is less than or equal to the electrokinetic pressure value, p^ek_c/p^ek_p, of at least one of said pumping conduits.

36. The electrokinetic device of claim 35, wherein p^ek_c/p^ek_p≦

0.5.

37. The electrokinetic device of claim 36, wherein p^ek_c/p^ek_p≦

0.1.

38. The electrokinetic device of claim 37, wherein p^ek_c/p^ek_p≦

0.01.

39. The electrokinetic device of claim 38, wherein p^ek_c/p^ek_p≦

0.001.

40. The electrokinetic device of claim 39, wherein p^ek_c/p^ek_p≦

0.0001.

41. The electrokinetic device of claim 35, wherein said conducting conduit hydrodynamic conductance, k_c, is greater than or equal to the hydrodynamic conductance, k_p, of at least one of said pumping conduits.

42. The electrokinetic device of claim 41, wherein k_c/k_p≧

2.

43. The electrokinetic device of claim 42, wherein k_c/k_p≧

10.

44. The electrokinetic device of claim 43, wherein k_c/k_p≧

100.

45. The electrokinetic device of claim 44, wherein k_c/k_p≧

1000.

46. The electrokinetic device of claim 45, wherein k_c/k_p≧

10,000.

47. The electrokinetic device of claim 35, wherein said conducting conduit electrical resistance, R_c, is greater than or equal to the electrical resistance, R_p, of at least one of said pumping conduits.

48. The electrokinetic device of claim 47, wherein R_c/R_p≧

2.

49. The electrokinetic device of claim 48, wherein R_c/R_p≧

5.

50. The electrokinetic device of claim 49, wherein R_c/R_p≧

10.

51. The electrokinetic device of claim 50, wherein R_c/R_p≧

100.

52. The electrokinetic device of claim 35, wherein at least one of said conduits is a microscale conduit.

53. The electrokinetic device of claim 35, wherein said first electrode is at potential V1, said second electrode is at potential V2, said third electrode is at potential V3, and said fourth electrode is at potential V4, and wherein at least one of the differences (V1−

V2) and (V3−

V4) is not equal to zero.

54. The electrokinetic device of claim 53, wherein V1, V2, and V3 are selected so that (V2−

V1) and (V3−

V2) are oppositely signed.

55. The electrokinetic device of claim 53, wherein V1, V2, V3, and V4 are selected so that (V2−

V1) and (V4−

V3) are oppositely signed.

56. The electrokinetic device of claim 53, wherein V1, V2, V3, and V4 are selected so that (V2−

V1) and (V4−

V3) are same signed.

57. The electrokinetic device of claim 53, wherein V1 is equal to V4.

58. The electrokinetic device of claim 57, wherein said potentials V1 and V4 are ground potentials.

59. The electrokinetic device of claim 35, wherein said first porous dielectric material is the same as said second porous dielectric material.

60. The electrokinetic device of claim 35, wherein said first porous dielectric material is different from said second porous dielectric material.

61. The electrokinetic device of claim 60, wherein said first and said second porous dielectric materials have oppositely-signed zeta potentials when contacted with a pumping fluid.

62. The electrokinetic device of claim 35, wherein said conducting conduit includes a porous material.

63. The electrokinetic device of claim 35, wherein said device is capable of generating an electroosmotic force on an aqueous fluid.

64. The electrokinetic device of claim 35, wherein said device is capable of generating an electroosmotic force on a fluid mixture comprising an aqueous component and an organic component.

65. The electrokinetic device of claim 35, wherein said device is capable of generating 0.05 psi/volt applied across said first and said second pumping conduits.

66. The electrokinetic device of claim 65, wherein said device is capable of generating 2 psi/volt applied across said first and said second pumping conduits.

67. A method of controlling the flow of a fluid, comprising:

contacting at least one end of said first pumping conduit or said second pumping conduit of the electrokinetic device of claim 35 with a fluid; and

supplying potential V1 to a first electrode in electrical communication with said first pumping conduit first end, potential V2 to a second electrode in electrical communication with said first junction, potential V3 to a third electrode in electrical communication with said second junction, and potential V4 to a fourth electrode in electrical communication with said second pumping conduit second end.

68. The method of claim 67, wherein at least one of said differences (V1−

V2) and (V3−

V4) is not equal to zero.

69. The method of claim 67, wherein at least one of said differences (V1−

V2) and (V3−

V4) is less than 200 volts.

70. The method of claim 67, wherein V1, V2, and V3 are selected so that (V2−

V1) and (V3−

V2) are oppositely signed.

71. The method of claim 67, wherein V1, V2, V3, and V4 are selected so that (V2−

V1) and (V4−

V3) are oppositely signed.

72. The method of claim 67, wherein V1, V2, V3, and V4 are selected so that (V2−

V1) and (V4−

V3) are same signed.

73. The method of claim 67, wherein V1 is equal to V4.

74. The method of claim 73, wherein said potentials V1 and V4 are ground potentials.

75. The method of claim 67, further comprising supplying a pressure-driven flow to said device, and modulating said pressure-driven flow by an electroosmotically-driven flow component generated within said first or said second pumping conduit.

76. An electrokinetic device, comprising:

a first pumping conduit having a first end and a second end, and including a first porous dielectric material;

a first conducting conduit having a first end and a second end, said first pumping conduit second end and said first conducting conduit first end connecting at a first junction;

a second pumping conduit having a first end and a second end, and including a second porous dielectric material, said second pumping conduit first end connecting to said first conducting conduit second end at a second junction;

a second conducting conduit having a first end and a second end, said second pumping conduit second end connecting to said second conducting conduit first end at a third junction; and

at least one electrode in electrical communication with each of said pumping conduits and said conducting conduits, the total number of electrodes being odd.

77. The electrokinetic device of claim 76, wherein said odd number of electrodes comprises a first electrode at potential V1 in electrical communication with said first pumping conduit first end, a second electrode at potential V2 in electrical communication with said first junction, a third electrode at potential V3 in electrical communication with said second junction, a fourth electrode at potential V4 at said third junction, and a fifth electrode at potential V5 at said second conducting conduit second end, and wherein at least one of the differences (V1−

V2) and (V3−

V4) does not equal zero.

78. The electrokinetic device of claim 77, wherein V2 does not equal V3.

79. The electrokinetic device of claim 77, wherein V4 does not equal V5.

80. The electrokinetic device of claim 77, wherein V1, V2, V4, and V5 are selected so that (V2−

V1) and (V5−

V4) are oppositely signed.

81. The electrokinetic device of claim 77, wherein V1 is equal to V5.

82. The electrokinetic device of claim 81, wherein said potentials V1 and V5 are ground potentials.

83. The electrokinetic device of claim 76, wherein any of said conducting conduits includes a porous material.

84. The electrokinetic device of claim 76, wherein said device is capable of generating an electroosmotic force on an aqueous fluid.

85. The electrokinetic device of claim 76, wherein said device is capable of generating an electroosmotic force on a fluid mixture comprising an aqueous component and an organic component.

86. The electrokinetic device of claim 76, wherein said device is capable of generating 0.05 psi/volt applied across said first and said second pumping conduits.

87. The electrokinetic device of claim 76, wherein said device is capable of generating 2 psi/volt applied across said first and said second pumping conduits.

88. The electrokinetic device of claim 76, wherein the hydrodynamic conductance, k_c, of at least one of said conducting conduits is greater than the hydrodynamic conductance, k_p, of at least one of said pumping conduits.

89. The electrokinetic device of claim 88, wherein k_c/k_p≧

2.

90. The electrokinetic device of claim 89, wherein k_c/k_p≧

10.

91. The electrokinetic device of claim 90, wherein k_c/k_p≧

100.

92. The electrokinetic device of claim 91, wherein k_c/k_p≧

1000.

93. The electrokinetic device of claim 92, wherein k_c/k_p≧

10,000.

94. The electrokinetic device of claim 76, wherein the electrokinetic pressure value, p^ek_c, of at least one of said conducting conduits is less than the electrokinetic pressure value, p^ek_c, of at least one of said pumping conduits.

95. The electrokinetic device of claim 94, wherein p^ek_c/p^ek_p≦

0.5.

96. The electrokinetic device of claim 95, wherein p^ek_c/p^ek_p≦

0.1.

97. The electrokinetic device of claim 96, wherein p^ek_c/p^ek_p≦

0.01.

98. The electrokinetic device of claim 97, wherein p^ek_c/p^ek_p≦

0.001.

99. The electrokinetic device of claim 98, wherein p^ek_c/p^ek_p≦

0.0001.

100. The electrokinetic device of claim 76, wherein the electrical resistance, R_c, of at least one of said conducting conduits is greater than or equal to the electrical resistance, R_p, of at least one of said pumping conduits.

101. The electrokinetic device of claim 100, R_c/R_p≧

2.

102. The electrokinetic device of claim 101, wherein R_c/R_p≧

5.

103. The electrokinetic device of claim 102, wherein R_c/R_p≧

10.

104. The electrokinetic device of claim 103, wherein R_c/R_p≧

100.

105. The electrokinetic device of claim 76, wherein said odd number of electrodes comprises a first electrode at potential V1 in electrical communication with said first pumping conduit first end, and an N^th electrode at potential VN in electrical communication with a second end of a terminal conducting conduit.

106. The electrokinetic device of claim 105, wherein V1 is equal to VN.

107. The electrokinetic device of claim 106, wherein said potentials V1 and VN are ground potentials.

108. A method of controlling the flow of a fluid, comprising:

contacting at least one end of said first pumping conduit or said second pumping conduit of the electrokinetic device of claim 76 with a fluid; and

supplying potential V1 to a first electrode in electrical communication with said first pumping conduit first end, potential V2 to a second electrode in electrical communication with said first junction, potential V3 to a third electrode in electrical communication with said second junction, potential V4 to a fourth electrode in electrical communication with said third junction, and potential V5 to said second conducting conduit second end.

109. The method of claim 108, wherein at least one of the differences (V1−

V2) and (V3−

V4) is not equal to zero.

110. The method of claim 108, wherein V2 does not equal V3.

111. The method of claim 108, wherein V4 does not equal V5.

112. The method of claim 108, wherein V1, V2, V4, and V5 are selected so that (V2−

V1) and (V5−

V4) are oppositely signed.

113. The method of claim 108, wherein V1 is equal to V5.

114. The method of claim 113, wherein said potentials V1 and V5 are ground potentials.

115. The method of claim 108, further comprising supplying a pressure-driven flow to said device, and modulating said pressure-driven flow by an electroosmotically-driven flow component generated within said first or said second pumping conduit.

116. An electrokinetic device, comprising:

a pumping conduit having a first end and a second end, and including a porous dielectric material;

a conducting conduit having a first end and a second end, said pumping conduit second end and said conducting conduit first end connecting at a junction; and

a first electrode at potential V1 in electrical communication with said pumping conduit first end, a second electrode at potential V2 in electrical communication with said junction, and a third electrode at potential V3 in electrical communication with said conducting conduit second end.

117. The electrokinetic device of claim 116, wherein V1 does not equal V2.

118. The electrokinetic device of claim 116, wherein V3 does not equal V2.

119. The electrokinetic device of claim 116, wherein V1, V2, and V3 are selected so that (V2−

V1) and (V3−

V2) are oppositely signed.

120. The electrokinetic device of claim 116, wherein V1 is equal to V3.

121. The electrokinetic device of claim 120, wherein said potentials V1 and V3 are ground potentials.

122. The electrokinetic device of claim 116, wherein said conducting conduit includes a porous material.

123. The electrokinetic device of claim 116, wherein said conducting conduit hydrodynamic conductance, k_c, is greater than said pumping conduit hydrodynamic conductance, k_p.

124. The electrokinetic device of claim 123, wherein k_c/k_p≧

2.

125. The electrokinetic device of claim 124, wherein k_c/k_p≧

10.

126. The electrokinetic device of claim 125, wherein k_c/k_p≧

100.

127. The electrokinetic device of claim 126, wherein k_c/k_p≧

1000.

128. The electrokinetic device of claim 127, wherein k_c/k_p≧

10,000.

129. The electrokinetic device of claim 116, wherein said conducting conduit electrokinetic pressure value, p^ek_c, is less than said pumping conduit electrokinetic pressure value, p^ek_p.

130. The electrokinetic device of claim 129, wherein p^ek_c/p^ek_p≦

0.5.

131. The electrokinetic device of claim 130, wherein p^ek_c/p^ek_p≦

0.1.

132. The electrokinetic device of claim 131, wherein p^ek_c/p^ek_p≦

0.01.

133. The electrokinetic device of claim 132, wherein p^ek_c/p^ek_p≦

0.001.

134. The electrokinetic device of claim 133, wherein p^ek_c/p^ek_p≦

0.0001.

135. The electrokinetic device of claim 116, wherein said conducting conduit electrical resistance, R_c, is greater than or equal to said pumping conduit electrical resistance, R_p.

136. The electrokinetic device of claim 135, wherein R_c/R_p≧

2.

137. The electrokinetic device of claim 136, wherein R_c/R_p≧

5.

138. The electrokinetic device of claim 137, wherein R_c/R_p≧

10.

139. The electrokinetic device of claim 138, wherein R_c/R_p≧

100.

140. The electrokinetic device of claim 116, wherein said device is capable of generating 0.05 psi/volt applied across said pumping conduit.

141. The electrokinetic device of claim 140, wherein said device is capable of generating 0.1 psi/volt applied across said pumping conduit.

142. The electrokinetic device of claim 141, wherein said device is capable of generating 1 psi/volt applied across said pumping conduit.

143. The electrokinetic device of claim 142, wherein said device is capable of generating 10 psi/volt applied across said pumping conduit.

144. An electrokinetic device, comprising:

a first pumping conduit having a first end and a second end, and including a first porous dielectric material;

a first conducting conduit having a first end and a second end, said first pumping conduit second end and said first conducting conduit first end connecting at a first junction;

a second pumping conduit having a first end and a second end, and including a second porous dielectric material, said second pumping conduit first end connecting to said first conducting conduit second end at a second junction;

a second conducting conduit having a first end and a second end, said second pumping conduit second end connecting to said second conducting conduit first end at a third junction;

and a first electrode at potential V1 in electrical communication with said first pumping conduit first end, a second electrode at potential V2 in electrical communication with said first junction, a third electrode at potential V3 in electrical communication with said second junction, a fourth electrode at potential V4 in electrical communication with said third junction, and a fifth electrode at potential V5 in electrical communication with said second conducting channel second end.

145. The device of claim 144, wherein at least one of the differences (V1−

V2) and (V3−

V4) does not equal zero.

146. The electrokinetic device of claim 144, wherein V2 does not equal V3.

147. The electrokinetic device of claim 144, wherein V4 does not equal V5.

148. The electrokinetic device of claim 144, wherein V1, V2, V4, and V5 are selected so that (V2−

V1) and (V5−

V4) are oppositely signed.

149. The electrokinetic device of claim 144, wherein V1 is equal to V5.

150. The electrokinetic device of claim 149, wherein said potentials V1 and V5 are ground potentials.

151. The electrokinetic device of claim 144, wherein any of said conducting conduits includes a porous material.

152. The electrokinetic device of claim 144, wherein said device is capable of generating 0.05 psi/volt applied across said first and said second pumping conduits.

153. The electrokinetic device of claim 152, wherein said device is capable of generating 2 psi/volt applied across said first and said second pumping conduits.

154. The electrokinetic device of claim 144, wherein the hydrodynamic conductance, k_c, of at least one of said conducting conduits is greater than the hydro dynamic conductance, k_p, of at least one of said pumping conduits.

155. The electrokinetic device of claim 154, wherein k_c/k_p≧

2.

156. The electrokinetic device of claim 155, wherein k_c/k_p≧

10.

157. The electrokinetic device of claim 156, wherein k_c/k_p≧

100.

158. The electrokinetic device of claim 157, wherein k_c/k_p≧

1000.

159. The electrokinetic device of claim 158, wherein k_c/k_p≧

10,000.

160. The electrokinetic device of claim 144, wherein the electrokinetic pressure value, p^ek_c, of at least one of said conducting conduits is less than the electrokinetic pressure value, p^ek_c, of at least one of said pumping conduits.

161. The electrokinetic device of claim 160, wherein p^ek_c/p^ek_c≦

0.5.

162. The electrokinetic device of claim 161, wherein p^ek_c/p^ek_c≦

0.1.

163. The electrokinetic device of claim 162, wherein p^ek_c/p^ek_c≦

0.01.

164. The electrokinetic device of claim 163, wherein p^ek_c/p^ek_c≦

0.001.

165. The electrokinetic device of claim 164, wherein p^ek_c/p^ek_c≦

0.0001.

166. The electrokinetic device of claim 144, wherein the electrical resistance, R_c, of at least one of said conducting conduits is greater than or equal to the electrical resistance, R_p, of at least one of said pumping conduits.

167. The electrokinetic device of claim 166, wherein R_c/R_p≧

0.2.

168. The electrokinetic device of claim 167, wherein R_c/R_p≧

5.

169. The electrokinetic device of claim 168, wherein R_c/R_p≧

10.

170. The electrokinetic device of claim 169, wherein R_c/R_p≧

100.