LIQUID LENS WITH MAGNIFICATION CONTROL

• US 20150331156A1
• Filed: 11/13/2013
• Published: 11/19/2015
• Est. Priority Date: 07/26/2011
• Status: Active Grant

• Current Assignee: Rensselaer Polytechnic Institute
• Original Assignee: Rensselaer Polytechnic Institute
• Inventors: HIRSA, Amir H.
• Granted Patent: US 9,488,758 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 26/004 based on a displacement or a deformation of a fluid
• CPC Class Codes: G02B 3/14 of variable focal length
• CPC Class Codes: Y10T 29/49886 to roughen surface

Abstract

A liquid lens structure and method of fabrication are provided. The liquid lens includes a substrate with a channel opening extending through the substrate. A liquid drop is disposed within the channel and an enclosure at least partially surrounds the substrate, and forms a chamber. The liquid drop resides within the chamber, and a second liquid is disposed within the chamber in direct or indirect contact with the liquid drop at a first interface and a second interface. The first and second interfaces define first and second protruding liquid portions relative to the first and second surfaces, respectively. Taken together, the first and second liquid portions define a total protruding liquid volume. A lens magnification control is provided for adjusting magnification of the liquid lens by increasing or decreasing the total protruding liquid volume defined relative to the first and second surfaces.

Claims

1. An apparatus comprising:

a liquid lens comprising;

a substrate comprising at least one channel extending through the substrate between a first surface and a second surface of the substrate;

a liquid drop comprising a first liquid, the liquid drop being disposed, in part, within one channel of the at least one channel extending through the substrate;

an enclosure at least partially surrounding the substrate and comprising a chamber, the one channel of the at least one channel extending through the substrate residing within the chamber of the enclosure;

a second liquid disposed within the chamber, the second liquid and the liquid drop comprising the first liquid being in one of direct or indirect contact within the chamber at a first interface and a second interface, the first interface defining a first protruding liquid portion relative to the first surface of the substrate, and the second interface defining a second protruding liquid portion relative to the second surface of the substrate, and taken together, the first and second protruding liquid portions defining a total protruding liquid volume; and

a lens magnification control for adjusting magnification of the liquid lens by increasing or decreasing the total protruding liquid volume defined relative to the first and second surfaces of the substrate.

2. The apparatus of claim 1, further comprising an actuator for oscillating the liquid drop within the one channel, the lens magnification control providing control of liquid lens magnification notwithstanding oscillation of the liquid drop within the one channel.

3. The apparatus of claim 1, further comprising an actuator for non-oscillatingly adjusting configuration of the liquid drop to adjust a focal distance of the liquid lens, wherein both magnification of the liquid lens and focal distance of the liquid lens may be adjusted.

4. The apparatus of claim 2, wherein the lens magnification control comprises an inner cavity within the substrate in fluid communication with the one channel of the at least one channel extending through the substrate, the liquid drop further comprising an inner droplet portion protruding from the one channel towards the inner cavity, and wherein the lens magnification control controls the total protruding liquid volume relative to the first and second surfaces of the substrate by controlling volume of the inner droplet portion protruding from the one channel of the substrate towards the inner cavity.

5. The apparatus of claim 4, wherein the at least one channel in the substrate comprises at least one first channel, and the lens magnification control further comprises:

at least one ferrofluid drop disposed, in part, within at least one second channel in the substrate, one ferrofluid drop of the at least one ferrofluid drop comprising an inner droplet portion extending into the inner cavity, the inner droplet portion of the liquid drop and the inner droplet portion of the one ferrofluid drop being in one of direct or indirect contact within the inner cavity; and

at least one electromagnetic driver to controllably adjust volume of the inner droplet portion of the one ferrofluid drop of the at least one ferrofluid droplet extending into the inner cavity, and thereby control volume of the inner droplet portion of the liquid drop protruding towards the inner cavity, and thus the total protruding liquid volume relative to the first and second surfaces of the substrate, and wherein the actuator comprises the at least one electromagnetic driver.

6. The apparatus of claim 5, wherein the inner droplet portion of the liquid drop and the inner droplet portion of the one ferrofluid drop are in indirect contact within the inner cavity via an interface liquid disposed within the inner cavity.

7. The apparatus of claim 6, wherein the interface liquid comprises the second liquid, the second liquid separating the inner droplet portion of the liquid drop and the inner droplet portion of the one ferrofluid drop within the inner cavity of the substrate.

8. The apparatus of claim 4, wherein the at least one channel in the substrate comprises at least one first channel, and the lens magnification control further comprises:

at least one deformable surface extending across at least one second channel in the substrate extending to the inner cavity;

an interface liquid disposed within the inner cavity, wherein the at least one deformable surface and the inner droplet portion of the liquid drop are in indirect contact via the interface liquid; and

a driver to controllably adjust position of the at least one deformable surface, and thereby control volume of the inner droplet portion of the liquid drop protruding towards the inner cavity, and thus the total protruding liquid volume relative to the first and second surfaces of the substrate, and wherein the actuator comprises the driver.

9. The apparatus of claim 4, wherein the first surface of the substrate facilitates defining a first chamber portion of the chamber, and the second surface of the substrate facilitates defining a second chamber portion of the chamber, and wherein the second liquid substantially fills the first chamber portion and the second chamber portion.

10. The apparatus of claim 9, wherein the second liquid and the liquid drop comprising the first liquid are immiscible and are in direct contact within the first chamber portion, and are in direct contact within the second chamber portion.

11. The apparatus of claim 2, further comprising at least one imaging sensor coupled to at least one imaging path passing through the liquid drop in the one channel for capturing an image through the liquid drop.

12. The apparatus of claim 3, wherein the actuator comprises multiple ferrofluid drops held in multiple second channels in the substrate extending between one of the first surface and the inner cavity, or the second surface and the inner cavity, each ferrofluid drop comprising a volume greater than a critical volume defined relative to a diameter of the respective second channel of the multiple second channels and functioning as a bi-stable capillary switching element, wherein each bi-stable capillary switching element can be toggled between a first state, where the ferrofluid drop resides principally within the chamber, and a second state, where the ferrofluid drop resides principally within the inner cavity of the substrate, and wherein one ferrofluid drop of the multiple ferrofluid drops is separably switchable from another ferrofluid drop of the multiple ferrofluid drops to facilitate tuning of the focal distance of the liquid lens, and wherein the lens magnification control comprises the actuator and adjusts magnification of the liquid lens by selectively switching the multiple ferrofluid drops to adjust the total protruding liquid volume relative to the first and second surfaces of the substrate.

13. A method of fabricating a liquid lens comprising:

obtaining a substrate, the substrate being non-wetting relative to a liquid drop;

providing at least one channel in the substrate extending from a first surface to a second surface thereof;

providing the liquid drop comprising a first liquid within one channel of the at least one channel extending through the substrate;

providing an enclosure at least partially surrounding the substrate and comprising a chamber, the one channel of the at least one channel extending through substrate residing within the chamber of the enclosure;

disposing a second liquid within the chamber, the second liquid and the liquid drop comprising the first liquid being in one of direct or indirect contact within the chamber at a first interface and a second interface, the first interface defining a first protruding liquid portion relative to the first surface of the substrate, and the second interface defining a second protruding liquid portion relative to the second surface of the substrate, and taken together, the first and second protruding liquid portions defining a total protruding liquid volume; and

providing a lens magnification control for adjusting magnification of the liquid lens by increasing or decreasing the total protruding liquid volume defined relative to the first and second surfaces of the substrate.

14. The method of claim 13, further comprising providing an actuator for oscillating the liquid drop within the channel, the lens magnification control providing control of liquid lens magnification notwithstanding oscillation of the liquid drop within the one channel.

15. The method of claim 13, further comprising providing an actuator for non-oscillatingly adjusting configuration of the liquid drop to adjust a focal distance of the liquid lens, wherein both magnification of the liquid lens and focal distance of the liquid lens may be adjusted.

16. The method of claim 14, wherein providing the lens magnification control comprises providing the substrate with an inner cavity in fluid communication with the one channel of the at least one channel extending through the substrate, the liquid drop further comprising an inner droplet portion protruding from the one channel towards the inner cavity, and wherein the lens magnification control controls the total protruding liquid volume defined relative to the first and second surfaces of the substrate by controlling volume of the inner droplet portion protruding from the one channel of the substrate towards the inner cavity.

17. The method of claim 14, further comprising providing at least one imaging sensor coupled to at least one imaging path passing through the first and second droplet portions of the liquid lens drop in the one channel for capturing an image through the first and second droplet portions of the liquid lens drop.