Electrochemical display and timing mechanism with migrating electrolyte

• US 5,930,023 A
• Filed: 04/27/1998
• Issued: 07/27/1999
• Est. Priority Date: 04/28/1997
• Status: Expired due to Term

• Current Assignee: Wisconsin Label Corporation (Multi-Color Corporation)
• Original Assignee: Wisconsin Label Corporation (Multi-Color Corporation)
• Inventors: Parker, Robert, Mitchell, Chauncey T. Jr., Verschuur, Gerrit L., Shadle, Mark A., Good, David M.
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): Lester, Evelyn A.
• Application Number:
  US09/067,114
• Time in Patent Office: 456 Days
• Field of Search: 359/265, 359/270, 359/272, 359/274, 429/93
• US Class Current: 359/270
• CPC Class Codes: G02F 1/1506 caused by electrodeposition, e.g. electrolytic deposition of an inorganic material on or close to an electrode
• CPC Class Codes: G02F 1/1508 using a solid electrolyte
• CPC Class Codes: G02F 1/153 Constructional details
• CPC Class Codes: G02F 1/1533 structural features not otherwise provided for
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G04F 1/00 Apparatus which can be set and started to measure-off predetermined or adjustably-fixed time intervals without driving mechanisms, e.g. egg timers
• CPC Class Codes: G09F 7/00 Signs, name or number plates, letters, numerals, or symbols vehicle registration number plates B60R13/10; Panels or boards show-cards G09F1/00; indicating arrangements for variable information G09F9/00, G09F11/00; illuminated signs G09F13/00; boards for notices or posters G09F15/00
• CPC Class Codes: G09F 9/00 Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the variable information is permanently attached to a movable support G09F11/00; abacus G06C1/00; slide-rules G06G1/00
• CPC Class Codes: H01M 6/38 by mechanical means
• CPC Class Codes: H01M 6/40 Printed batteries , e.g. thin film batteries
• CPC Class Codes: H01M 6/5044 Cells or batteries structurally combined with cell condition indicating means
• CPC Class Codes: Y10T 29/49108 Electric battery cell making

Abstract

Printed electrochemical display cells are arranged in layer form with two electrode layers and an electrolyte layer occupying distinct areas of a substrate. An electrolyte layer overlaps most of one electrode layer but contacts a smaller portion of the other electrode layer, which is made of a thin film. When activated, an electrochemical reaction progressively increases the area occupied by the electrolyte layer and progressively decreases the area occupied by the thin-film electrode layer. The thin-film electrode layer recedes at a boundary in common with the electrolyte layer and provides an irreversible indication of change at a rate governed by the electrochemical reaction.

Claims

1. An electrochemical display comprising:

first and second electrode layers having different electrode potentials;

an electrolyte layer overlapping said first electrode layer and forming a boundary with said second electrode layer for completing an ionically conductive pathway between said first and second electrode layers; and

said electrolyte boundary being movable together with a boundary of said second electrode layer extending the ionically conductive pathway from said first electrode layer in response to a flow of current between said first and second electrode layers for changing a visible appearance of the display.

2. The display of claim 1 in which said second electrode layer is made of a thin film capable of undergoing an electrochemical reaction that results in the progressive disappearance of said second electrode layer behind said moving boundary of the electrolyte layer.

3. The display of claim 2 in which said second electrode layer is made of a thin metal film deposited onto a transparent substrate.

4. The display of claim 2 in which said moving boundary of the electrolyte layer progressively increases an area covered by said electrolyte layer, and said moving boundary of the second electrode layer progressively decreases an area covered by said second electrode layer.

5. The display of claim 4 in which said first electrode layer covers a fixed area that is not affected by said moving boundaries of the electrolyte layer and the second electrode layer.

6. The display of claim 1 in which said first and second electrodes are relatively positioned so that at least portions of said first and second electrode layers are laid out side-by-side.

7. The display of claim 6 in which said second electrode layer has an extended portion supporting a switch contact for opening and closing an electronically conductive pathway between said first and second electrode layers.

8. The display of claim 6 in which said electrolyte layer overlaps a larger portion of said first electrode layer than said second electrode layer.

9. The display of claim 8 in which adjacent portions of said first and second electrode layers have an irregular-shaped lateral interface to enhance an electrochemical interaction between the electrode layers.

10. The display of claim 8 in which one of said first and second electrodes is funnel-shaped to promote migration of the electrolyte layer.

11. The display of claim 10 in which said second electrode is funnel-shaped having a wide end adjacent to said first electrode.

12. The display of claim 6 in which said first electrode layer overlaps said second electrode layer.

13. The display of claim 12 in which a dielectric layer electronically separates said first and second electrode layers.

14. The display of claim 1 in which said electrolyte layer has a limited viscosity that permits migration of said electrolyte boundary with said moving boundary of the second electrode layer.

15. The display of claim 14 in which said electrolyte layer is formed by an electrolytic adhesive.

16. The display of claim 14 in which said electrolyte layer is formed by an electrolytic gel.

17. The display of claim 1 in which said second electrode layer is supported on a transparent substrate, and said moving boundary of the second electrode layer gradually reveals a graphic image that becomes visible through said transparent substrate.

18. An irreversible electrochemical display comprising:

first and second electrode layers and an electrolyte layer occupying distinct areas of a substrate;

said electrolyte layer being in operative contact with said first and second electrode layers for completing an ionically conductive pathway between said first and second electrode layers;

an electronically conductive pathway that is closeable in support of an electrochemical reaction that progressively increases the area of the substrate occupied by said electrolyte layer and progressively decreases the area of the substrate occupied by said second electrode layer; and

said progressively increasing area of the electrolyte layer and said progressively decreasing area of the second electrode layer providing an irreversible indication of change at a rate governed by the electrochemical reaction.

19. The display of claim 18 in which the progressively increasing area of said electrolyte layer corresponds to the progressively decreasing area of said second electrode layer.

20. The display of claim 19 in which the area of the substrate occupied by said first electrode layer remains substantially constant throughout the electrochemical reaction.

21. The display of claim 18 in which said second electrode has a first portion in contact with said electrolyte layer and a second portion out of contact with said electrolyte layer, and said second portion of the second electrode is substantially larger in area than said first portion of the second electrode.

22. The display of claim 21 in which said first and second portions of the second electrode layer are separated by an interface with said electrolyte layer.

23. The display of claim 22 in which said progressive changes in area of the electrolyte layer and the second electrode layer occur at said interface.

24. The display of claim 23 in which said second portion of the second electrode layer has a length and a width, said length of said second electrode is greater than said width, and said interface extends in a direction across said width.

25. The display of claim 24 in which said second portion of the second electrode layer includes two ends and a middle along its length.

26. The display of claim 25 in which one of said ends is located on said substrate at a longer distance from said first electrode layer than from said middle of the second electrode.

27. The display of claim 25 in which both of said ends are located on said substrate at a shorter distance from said first electrode layer than from said middle of the second electrode.

28. The display of claim 25 in which one of said ends is ionically coupled to said first electrode through said electrolyte layer, and the other of said ends is electronically coupled to said first electrode through said electronically conductive pathway.

29. The display of claim 18 in which adjacent portions of said first and second electrode layers have an irregular-shaped lateral interface to enhance the electrochemical interaction between the electrode layers.

30. The display of claim 18 in which one of said first and second electrodes is funnel-shaped to promote migration of the electrolyte layer.

31. The display of claim 30 in which said second electrode is funnel-shaped having a wide end adjacent to said first electrode.

32. The display of claim 24 further comprising a graphics layer having a window aligned with said second electrode layer to reveal a progressive movement of said interface along said length of the second electrode.

33. The display of claim 24 further comprising a graphics layer having a window aligned with a limited portion of said length of the second electrode layer so that an initial movement of said interface along said length of the second electrode is blocked from view and a subsequent movement of said interface along said length of the second electrode is revealed as an indication of a predetermined amount of progress of the electrochemical reaction.

34. The display of claim 24 further comprising a graphics overlay having a first window aligned with said first portion of the second electrode layer and a second window aligned with said second portion of the second electrode layer to reveal initial and subsequent indications of the progress of the electrochemical reaction.

35. The display of claim 18 in which said electrolyte layer overlaps said first electrode layer within a first common area of said substrate.

36. The display of claim 35 in which said electrode overlaps a substantial portion of the first electrode layer.

37. The display of claim 35 in which said first and second electrodes overlap each other within a second common area of said substrate.

38. The display of claim 37 in which said first and second electrodes are separated within said second common area by a dielectric layer that electronically isolates said first and second electrode layers.

39. The display of claim 18 in which said electrolyte layer is a first of two electrolyte layers and further comprising third and fourth electrode layers and a second electrolyte layer.

40. The display of claim 39 in which said second electrolyte layer forms an ionically conductive pathway between said third and fourth electrode layers, and said electronically conductive pathway interconnects said first electrode layer with said third electrode layer and interconnects said second electrode layer with said fourth electrode layer.

41. The display of claim 40 in which said third and fourth electrode layers have different electrode potentials that generate a flow of current for assisting the electrochemical reaction that progressively decreases the area of the substrate occupied by said second electrode layer.

42. The display of claim 41 in which said first and second electrode layers have substantially equal electrode potentials.

43. The display of claim 42 in which three of said four electrode layers have the same electrode potential.

44. An electrochemical display comprising:

first and second electrode layers and an electrolyte layer each occupying distinct areas of one or more substrates;

an electronically conductive pathway for interconnecting said first and second electrode layers independent of said electrolyte layer;

an ionically conductive pathway for interconnecting said first and second electrode layers being formed at least in part by said electrolyte layer;

said electrolyte layer being initially operatively isolated from at least one of said first and second electrode layers for interrupting said ionically conductive pathway between said first and second electrode layers;

said ionically conductive pathway being closeable in support of an electrochemical reaction that progressively increases the area occupied by said electrolyte layer and progressively decreases the area occupied by said second electrode layer; and

said progressively increasing area of the electrolyte layer and said progressively decreasing area of the second electrode layer providing an indication of change at a rate governed by the electrochemical reaction.

45. The display of claim 44 in which the progressively increasing area of said electrolyte layer corresponds to the progressively decreasing area of said second electrode layer.

46. The display of claim 45 in which the area occupied by said first electrode layer remains substantially constant throughout the electrochemical reaction.

47. The display of claim 44 in which the progressive changes in the areas of the second electrode layer and the electrolyte layer take place at a common moving boundary that extends the ionically conductive pathway from the first electrode layer.

48. The display of claim 44 further comprising a protective layer that covers said electrolyte layer prior to completion of the ionically conductive pathway.

49. The display of claim 48 in which said electrolyte layer is made of an electrolytic adhesive, and said protective layer is a release layer.

50. A method of producing a progressive change in an electrochemical display cell comprising the steps of:

arranging a first electrode layer in an overlapping relationship with an electrolyte layer;

locating a boundary of the electrolyte layer in contact with a first portion of a second electrode layer providing an ionically conductive pathway between the first and second electrodes;

arranging a second portion of the second electrode layer out of contact with the electrolyte layer;

completing an electronically conductive pathway between the first and second electrodes;

initiating an electrochemical reaction eroding the first portion of the second electrode layer at the boundary of the electrolyte layer; and

continuing the electrochemical reaction extending the boundary of the electrolyte layer from the first electrolyte layer and progressively eroding the second portion of the second electrode layer at the extending boundary of the electrolyte layer for producing a progressive change useful for purposes of display.

51. The method of claim 50 in which said advancing boundary of the electrolyte increases a length of an ionically conductive pathway between said first and second electrode layers.

52. The method of claim 50 including a further step of adjusting a rate of the boundary advancement to perform a timing function.

53. The method of claim 52 in which said rate is adjusted by adjusting viscosity of the electrolyte layer.

54. The method of claim 53 in which said electrolyte layer is made of an electrolytic gel to advance said rate of boundary advancement.

55. The method of claim 53 in which said electrolyte layer is made of an electrolytic adhesive to retard said rate of boundary advancement.

56. The method of claim 52 in which said rate is adjusted by adjusting ionic conductivity of the electrolyte layer.

57. The method of claim 52 in which said rate is adjusted by adjusting a shape of the electrolyte layer.

58. The method of claim 52 in which said rate is adjusted by adjusting a shape of said second electrode layer.

59. The method of claim 52 in which said rate is adjusted by adjusting a thickness of said second electrode layer.

60. The method of claim 50 including the further step of forming the first and second electrode layers with different electrode potentials.

61. The method of claim 50 in which said second electrode layer is made of a thin film capable of undergoing an electrochemical reaction that results in a progressive disappearance of said second electrode layer behind said receding boundary of the second electrode layer.

62. A method of producing a progressive change in an electrochemical display cell comprising the steps of:

arranging first and second electrode layers and an electrolyte layer on a substrate, each occupying distinct areas of the substrate;

positioning the electrolyte layer in contact with the first and second electrode layers for completing an ionically conductive pathway between the first and second electrode layers;

supporting a flow of current along an electronically conductive pathway between the first and second electrode layers;

initiating an electrochemical reaction that progressively increases the area of the substrate occupied by the electrolyte layer and progressively decreases the area of the substrate occupied by the second electrode layer; and

providing a viewing opportunity for observing the decreasing area of the second electrode layer as an irreversible indication of change at a rate governed by the electrochemical reaction.

63. The method of claim 62 in which the progressively increasing area of said electrolyte layer corresponds to the progressively decreasing area of said second electrode layer.

64. The method of claim 63 in which the area of the substrate occupied by said first electrode layer remains substantially constant throughout the electrochemical reaction.

65. The method of claim 62 in which said step of arranging includes arranging the first and second electrode layers with an irregular-shaped lateral interface.

66. The method of claim 65 in which the irregular-shaped interface has a saw-tooth pattern.

67. The method of claim 62 in which said step of arranging includes arranging one of the first and second electrode layers with a funnel shape to promote migration of the electrolyte layer.

68. The method of claim 67 in which said step of arranging includes arranging the second electrode layer with a funnel shape having wide and narrow ends and positioning the wide end of the second electrode layer adjacent to the first electrode layer.