Porous structures produced by additive layer manufacturing

A method of forming a tubular structure including a first tube and a second tube comprising the steps of:

• depositing a first layer of a material onto a substrate;
• at least partially melting at least part of the deposited first layer of the material at predetermined locations;
• depositing successive layers of the material onto previously deposited and at least partially melted layers of the material;
• and at least partially melting at least part of each of the successive layers of the material at additional predetermined locations to form the first tube and the second tube such that the first tube defines a first central axis, has first and second ends, and is intersected with the second tube defining a second central axis transverse to the first central axis such that the second tube is spaced from the first and the second ends of the first tube and such that the second tube has an end that is spaced from the first tube,
• wherein the first tube has a porous surface around a circumference of the first tube, and
• wherein at least one portion of the first tube and at least one portion of the second tube are formed by a single one of the steps of at least partially melting a deposited layer of the material.

A method of forming a tubular structure including a first tube and a second tube comprising the steps of:

• successively depositing layers of a first material and at least partially melting at least a portion of each deposited layer of the first material at predetermined locations to form the first tube, wherein the first tube defines a first central axis;
• successively depositing layers of the first material or a second material and at least partially melting at least a portion of each of the deposited layers of the first material or the second material at additional predetermined locations to form the second tube, wherein the second tube defines a second central axis transverse to the first central axis and is attached to the first tube at an intersection;
• forming a first dielectric layer onto an at least partially melted layer of either one or both of the first material and the second material after at least partially cooling such partially melted layer;
• depositing a conductive powder material onto the formed dielectric layer;
• and
• at least partially melting at least a portion of the deposited conductive powder material at predetermined conductive locations to form a patterned conductive layer, wherein the patterned conductive layer, upon formation of the first tube and the second tube, is embedded in either one or both of the first tube and the second tube.