Claims
- 1. An apparatus for heating, measuring, and controlling the temperature of an ultra small volume comprising:
- a. an electrically non-conducting thin-walled microcapillary tube containing an electrically conductive material.
- b. said microcapillary tube having an external coating of an electrically conductive material.
- c. said electrically conductive materials meeting at one end of said microcapillary tube to form a heater-sensor portion jucture comprised of an area of electrical resistance along said juncture, said area of electrical resistance having a diameter between about 0.5 and about 5.0 microns, said heater-sensor portion having a heater portion and a heat-sensor portion.
- d. means for applying an electrical current to said electrically conductive materials to heat said heater portion.
- e. means for monitoring the electrical resistance of said heat-sensor portion to determine the temperature thereof, and
- f. means for controlling the supply of electrical current to said heater-sensor portion.
- 2. The apparatus of claim 1 wherein said external coating of electrically conductive material has an overcoating of metal.
- 3. The apparatus of claim 1 wherein said overcoating has an overcoat of an electrically nonconducting material.
- 4. The apparatus of claim 1 wherein the electrically conductive material within said microcapillary tube is an alloy having a melting point between about 100.degree. C. and about 250.degree. C.
- 5. The apparatus of claim 1 wherein the electrically conductive material in the external coating is a noble metal.
- 6. The apparatus of claim 5 wherein the noble metal is gold.
- 7. The apparatus of claim 1 wherein said external coating of electrically conductive material has a metal overcoat.
- 8. The apparatus of claim 7 wherein said overcoat is a noble metal.
- 9. The apparatus of claim 8 wherein said noble metal is silver.
- 10. The apparatus of claim 1 wherein the means for controlling the supply of electrical current is a closed-loop servo circuit responsive to said means for monitoring the electrical resistance of said heater-sensor portion.
Government Interests
This invention was made with U.S. Government support under NS-13194 awarded by the National Institute of Health. The Government has certain rights in this invention.
US Referenced Citations (5)