Hydrogel compositions, devices, and microscale components
The invention provides hydrogel compositions, components, and hydrogel-actuated or mediated devices, and methods for the incorporation of hydrogel microscale components in microscale devices and systems. The methods and devices result in active microvalves that are useful in microfluidic applications, including analyte sensing, in process chemical and fermentation stream monitoring, and drug delivery. In particular, the devices are useful for controlled drug delivery either in response to a pre-determined stimulus or for pulsatile delivery.
1. An implantable, hydrogel-actuated microvalve comprising:
(a) a first substrate permeable to a predetermined chemical compound;
(b) a volume-responsive hydrogel adjacent to the first substrate permeable to the predetermined chemical compound, the volume-responsive hydrogel undergoing a volume change in response to the predetermined chemical compound;
(c) a second substrate adjacent to the volume-responsive hydrogel, the second substrate deformable in response to the volume-responsive hydrogel; and
(d) a third substrate adjacent to the second substrate, the third substrate comprising an orifice capable of being sealed by the second substrate upon the deformation of the second substrate in response to a change in volume of the hydrogel.
2. An implantable, hydrogel-actuated microvalve comprising:
(a) a first substrate permeable to a predetermined chemical compound;
(b) a volume-responsive hydrogel adjacent to the first substrate permeable to the predetermined chemical compound, the volume-responsive hydrogel undergoing a volume change in response to the predetermined chemical compound;
(c) a second substrate adjacent to the volume-responsive hydrogel, the second substrate deformable in response to the volume-responsive hydrogel;
(d) a third substrate adjacent to the second substrate, the third substrate comprising a member, the member moveable in response to deformation of the second substrate in response to a change in volume of the hydrogel;
(e) a fourth substrate adjacent to the third substrate, the fourth substrate comprising an orifice capable of being sealed by the member of the third substrate upon movement of the member.
3. An implantable, hydrogel-actuated microvalve comprising:
(a) a first substrate permeable to a predetermined chemical compound;
(b) a volume-responsive hydrogel adjacent to the first substrate permeable to the predetermined chemical compound, the volume-responsive hydrogel capable of undergoing a volume change in response to the predetermined chemical compound;
(c) a second substrate adjacent to the volume-responsive hydrogel, the second substrate deformable in response to the volume-responsive hydrogel;
(d) a third substrate adjacent to the second substrate, the third substrate comprising a member, the member moveable in response to deformation of the second substrate; and
(e) a fourth substrate adjacent to the third substrate, the fourth substrate comprising a flexible body, the flexible body controlling access, upon cooperative movement of the member with the volume-responsive hydrogel, to a channel disposed between the third substrate and the fourth substrate.
4. The hydrogel-actuated microvalve of any one of claims 1 - 3 , wherein the first substrate is resistant to deformation.
5. The hydrogel-actuated microvalve of any one of claims 1 - 3 , wherein the first substrate comprises a porous glass plate.
6. The hydrogel-actuated microvalve of any one of claims 1 - 3 , wherein the first substrate comprises a porous aluminum oxide plate.
7. The hydrogel-actuated microvalve of any one of claims 1 - 3 , wherein the first substrate comprises a porous plate having homogenous pores in the range of about 10 nm to about 50 μm.
8. The hydrogel-actuated microvalve of any one of claims 1 - 3 , wherein the first substrate comprises a porous plate having a thickness of about 50 to about 1000 μm.
9. The hydrogel-actuated microvalve of any one of claims 1 - 3 , wherein the volume-responsive hydrogel undergoes a volume increase or a volume decrease in response to the predetermined chemical compound glucose.
10. The hydrogel-actuated microvalve of claim 9 , wherein the hydrogel comprises 3-methacrylamidophenylboronic acid and wherein the hydrogel undergoes a volume increase in response to glucose.
11. The hydrogel-actuated microvalve of claim 9 , wherein the hydrogel comprises 3-acrylamido-4-nitrobenzeneboronic acid and wherein the hydrogel undergoes a volume decrease in response to glucose.
12. The hydrogel-actuated microvalve of any one of claims 1 - 3 , wherein the second substrate is selected from the group consisting of a low modulus silicone, neoprene, and isoprene rubber.
13. A catheter comprising the hydrogel-actuated microvalve of any one of claims 1 - 3 .