Painless injector

1. An apparatus for use with tissue of a subject, comprising:

a substance configured to be injected into the tissue; and

first and second tissue-squeezing surfaces configured to be placed on first and second sides of the tissue, the first and second tissue-squeezing surfaces exerting pressure on the tissue by being moved toward each other in response to a squeezing force, the first and second tissue-squeezing surfaces facilitating injection of the substance into the tissue by releasing the substance upon breaking or decoupling an anchor coupled to the tissue-squeezing surfaces in response to application of the squeezing force,

wherein the tissue includes skin of the subject, and wherein the tissue-squeezing surfaces comprise skin-squeezing surfaces configured to exert pressure on the subject's skin by being moved toward each other in response to a squeezing force.

2. The apparatus according to claim 1 , wherein at least one of the tissue-squeezing surfaces comprises an array of microneedles, the microneedles being configured to exert pressure on the tissue and to penetrate the tissue in response to the application of the squeezing force.

3. The apparatus according to claim 2 , wherein the substance is disposed on a surface of the microneedles.

4. The apparatus according to claim 2 , further comprising a substance reservoir, wherein when the squeezing force is not applied, the substance is disposed within the substance reservoir, and wherein the substance is configured to be injected into the tissue from the reservoir via the microneedles, in response to the application of the squeezing force.

5. The apparatus according to claim 1 , wherein when the squeezing force is not applied, the substance is disposed at a first site that is not between the squeezing surfaces, and wherein the apparatus is configured to convey the substance from the first site to a second site that is between the squeezing surfaces, in response to the application of the squeezing force.

6. The apparatus according to claim 5 , further comprising a syringe and a needle coupled thereto, disposed at the first site when the squeezing force is not applied, wherein the substance is disposed within the syringe, and wherein the needle is configured to penetrate the tissue and release the substance into the tissue in response to the application of the squeezing force.

7. The apparatus according to claim 5 , wherein the apparatus is configured to rapidly convey the substance to the second site in response to the squeezing force exceeding a threshold.

8. The apparatus according to claim 7 , wherein the threshold force is defined as a force generated between one of the squeezing surfaces and the tissue, and wherein the apparatus is configured such that the threshold force is applied at a contact pressure of at least 500 g/cm2.

9. The apparatus according to claim 5 , wherein the substance comprises a solid mass, and wherein the solid mass is shaped to penetrate the tissue in response to the application of the squeezing force.

10. The apparatus according to claim 9 , wherein the apparatus is configured to hold the solid mass at the first site when the squeezing force is not applied, and to decouple the solid mass from at least one of the squeezing surfaces after injection of the solid mass into the tissue.

11. The apparatus according to claim 1 , wherein the squeezing force is applied generally perpendicularly to the first and second sides of the tissue.

12. An apparatus for use with a syringe that has a syringe needle, the apparatus comprising:

pinching surfaces configured to be disposed distal to a distal tip of the syringe needle, and to facilitate penetration of tissue of a subject by the distal tip of the syringe needle, by pinching a fold of tissue toward the distal tip of the syringe needle until the distal tip of the syringe needle is disposed within the fold of tissue; and one or more operating elements configured to operate the pinching surfaces, at least a portion of the operating elements move radially outwardly beyond the syringe when the pinching surfaces pinch the fold of tissue,

wherein the tissue includes internal tissue of the subject, and wherein the pinching surfaces are configured to contact the subject's internal tissue and facilitate penetration of the subject's internal tissue by the distal tip of the syringe needle.

13. The apparatus according to claim 12 , wherein the pinching surfaces are configured to pinch the fold of tissue using a pinching pressure of at least 200 g/cm2.

14. The apparatus according to claim 13 , wherein the pinching surfaces are configured to pinch the fold of tissue using a pinching pressure of 200 g/cm2 to 2000 g/cm2.

15. An apparatus comprising:

a syringe that comprises:

a syringe needle;

a barrel;

a plunger; and

pinching surfaces disposed distal to a distal tip of the syringe needle, and configured to facilitate penetration of tissue of a subject by the distal tip of the syringe needle, by pinching a fold of tissue toward the distal tip of the syringe needle until the distal tip of the syringe needle is disposed within the fold of tissue; and two operating elements each configured to operate one of the pinching surfaces, each operating element being positioned entirely exterior to the barrel.