Lock-release polymerization
Techniques are provided to independently control 3D shape and chemistry of rapidly produced colloids. A pre-polymer mixture including a monomer is made to flow into a channel with insular relief in a wall at a known location of the channel. A stimulus that polymerizes the pre-polymer mixture is directed onto the known location to form a structure locked in place at the known location by the insular relief. A pressure is applied to the channel that is sufficient to deflect the wall having the insular relief sufficiently to release a hydrogel particle comprising the structure.
1. An apparatus for synthesizing hydrogel particles comprising a body structure having formed therein a channel with insular relief in a top wall of the channel at a first location configured for particle synthesis, wherein the insular relief extends at most a first distance in a range from 1 to 250 microns perpendicular from a bottom surface of the top wall at the first location such that at least one wall of the top wall and bottom wall opposite the to wall at the first location is configured to deflect more than the first distance away from the opposite wall at applied pressures in a range from about 5 to about 15 pounds per square inch (psi).
2. An apparatus as recited in claim 1 , wherein the channel is a microfluidic channel, and the hydrogel particle is a hydrogel microparticle.
3. An apparatus as recited in claim 2 , wherein the first distance is about 30 microns, and the first pressures is about five pounds per square inch.
4. An apparatus as recited in claim 2 , wherein the first distance is about 250 microns, and the first pressures is about five pounds per square inch.
5. An apparatus as recited in claim 1 , wherein the body structure comprises polydimethylsiloxane (PDMS).
6. An apparatus as recited in claim 1 , wherein a thickness of the top wall with the insular relief is about 200 microns and a width of the wall of the channel is about 1000 microns.
7. An apparatus as recited in claim 1 , wherein the first distance is in a range from about 10 microns to about 30 microns.