With six CAR T cell therapy products currently approved by the FDA for the treatment of hematological cancers, there are increasing efforts to develop novel and better manufacturing technologies and processes to improve efficacy, reduce variability, and reduce cost. However, due to limited or costly materials, such as human PBMCs and viral vectors, research- and preclinical-scale experiments in cell therapy are often done in milliliter-sized static culture with minimal environmental control, which can result in variabilities that may prove difficult to translate to larger culture systems. We leveraged an automated perfusion microbioreactor, which can replicate bench-scale perfusion processes, to generate functional CAR T cells at high cell densities in a 2-mL culture volume. We showed that with improved media exchange from continuous perfusion, cell expansion is improved. These proof-of-concept data demonstrate the utility of the system as both a process development tool as well as a potential future manufacturing platform.