Fig 1.
(A) Axis of symmetry diagram of perfusion bioreactor with a gas permeable wall. Oxygen is allowed to diffuse radially into the bioreactor. R2 is the radius of the PDMS cylinder, R1 is the radius of the scaffold volume of the bioreactor, and L is the length. In the equation development, the radial coordinate was denoted by r and the longitudinal coordinate by z (measured from the inlet). (B) The experiments were also performed in a batch configuration where the medium was replaced every two days, however oxygen could still diffuse through the wall. (C) Traditional packed/fixed bed bioreactor where all the nutrients and oxygen are provided by medium perfusion alone. (D) Further enhancement of the design by incorporating a central capillary with outer wall radius Rw and lumen Rc in the centre of the reactor provides an additional oxygen source.