Glass-metal feedthrough

1. A glass-metal feedthrough, consisting of:

a glass material having a coefficient of expansion α glass ;

an external conductor having a coefficient of expansion α external that is greater than the coefficient of expansion of the glass material α glass , a difference between the coefficient of expansion of the external conductor α external and the coefficient of expansion of the glass material α glass is at least 2 ppm/K in a temperature range of 20° C. to a glass transformation temperature of the glass material, the external conductor consisting of a nickel-free, non-corrosive, chemically stable austenitic steel; and

an internal conductor having a coefficient of expansion α internal that is greater than the coefficient of expansion of the glass material α glass , the internal conductor directly contacting the glass material and consisting of one of the following materials:

steel;

stainless steel;

nickel-free ferritic stainless steel;

molybdenum;

tungsten;

platinum;

niobium;

titanium; or

platinum and iridium; wherein the coefficient of expansion of the internal conductor α internal and the coefficient of expansion of the external conductor αexternal are such that a joint pressure on the internal conductor of at least 30 MPa is generated in the temperature range of 20° C. to the glass transformation temperature of the glass material.

2. The glass-metal feedthrough of claim 1 , wherein the coefficient of expansion of the internal conductor αinternal is 1.1 times to 4 times greater than the coefficient of expansion of the glass material α glass .

3. An element for insertion into or attachment to a human or animal body or biological living cells containing cell cultures, said element comprising:

a glass-metal feedthrough comprising:

a glass material having a coefficient of expansion α glass ;

an external conductor having a coefficient of expansion α external that is greater than the coefficient of expansion of the glass material α glass , a difference between the coefficient of expansion of the external conductor α external and the coefficient of expansion of the glass material α glass is at least 2 ppm/K in a temperature range of 20° C. to a glass transformation temperature of the glass material, the external conductor consisting of an austenitic steel; and

an internal conductor having a coefficient of expansion α internal that is greater than the coefficient of expansion of the glass material α glass , wherein the external conductor and the internal conductor consist of metals which are configured to come into contact with the human or animal body or the cell cultures and do not release at least one of any nickel or any chrome, the internal conductor directly contacting the glass material and consisting of one of the following materials:

steel;

stainless steel;

ferritic stainless steels;

platinum;

platinum and iridium;

niobium;

titanium;

molybdenum;

tungsten; and

combinations thereof; wherein the coefficient of expansion of the internal conductor α internal and the coefficient of expansion of the external conductor α external are such that a joint pressure on the internal conductor of at least 30 MPa is generated in the temperature range of 20° C. to the glass transformation temperature of the glass material.

4. The element of claim 3 , wherein the metal of the internal conductor consist of at least one of nickel-free steel or chrome-free steel at least in surface areas which are configured to come into contact with the human or animal body or with biological cells of the cell culture in their operational use.