3-D printed probes for bioprocesses

A probing device for monitoring a reactor, the probing device comprising:

• a tip section having a sample detection region between an upper portion and a lower portion of the tip section;
• a transmission rod window fitted in a cavity formed by 3D printing in the upper portion;
• a detection rod window fitted in a cavity formed by 3D printing in the lower portion of the tip section,
• wherein,
• the transmission rod window and the detection rod window define a pathlength traveled by light in the sample detection region, wherein the pathlength is within a range of from about 2 millimeters and 20 millimeters.

A probing device comprising:

• a tube enclosing a first optical fiber and a second optical fiber;
• a tip having a sample detection region and a bottom end designed for total internal reflection,
• wherein,
• a light pathway follows the first optical fiber, enters the tip, passes through a sample detection region, undergoes total internal reflection in the bottom end, exits the tip and enters the second optical fibers, wherein a pathlength of the sample detection region is within a range of from about 2 millimeters and 20 millimeters.

A probing device for monitoring a reactor, the probing device comprising:

• a free space optical beam path enclosed in an inner tube, the inner tube being positioned within an outer tube in an off-center geometry;
• a tip section having a sample detection region defined by a gap between a transmission rod and a detection rod;
• and
• a photodetector housed in the tip section for detecting light received through the detection rod.