Advancements in robotic technologies have enabled a significant improvement in the clinical efficacy of prosthetic limbs for persons with upper and lower-extremity amputations. However, significant challenges still remain in establishing a biomimetic bidirectional neural communication between amputees and their external powered prostheses. Regenerative peripheral nerve interfaces may offer a high-resolution alternative to conventional nerve interface technologies for their unique potential to provide increased biospatial resolution for both the control of and feedback from an external powered prosthesis. Here, we present three active 3-D microchannel arrays, having 16-20 channels and each 200 μm by 200 μm: one passive (without integrated electrodes), one active (with integrated electrodes), and one active with a porous collagen scaffold. With the array positioned between proximal and distal nerve stumps, we evaluate their effectiveness in tibial n. regeneration in vivo in both rats (N=4) and ferrets (N=4). Using immunofluorescence, we report robust mixed sensory and motor nerve regeneration through the microchannels in all rats, and weak regeneration in 2 of 4 ferrets, suggesting both interspecies regeneration variability and the lack of benefit of axially oriented collagen in improving ferret nerve regeneration through microchannels.