This study develops an air breathing pump driven by a piezoelectric actuator for a proton exchange membrane fuel cell (PEMFC) stack. Permanent magnets are combined with a piezoelectric actuator to drive three air breathing pumps using magnetic force. This design enables the pump to provide a sufficient amount of air simultaneously to six cathode flow field plates in a stack of three "bi-cell PZTmag-PEMFCs". When both the PZTmag and the PDMSmag had a magnet with a 6-mm diameter and 1-mm thickness, a maximum amplitude of 87 µm was generated at 0.03 W of power under operating conditions of 70 Hz and 40 V. In computational fluid dynamics (CFD), when the nozzle and the diffuser of an air breathing pump have an aspect ratio of 13.13, air flow distributes uniformly inside the pump, thus allowing for uniform transmission of oxygen to the membrane electrode assembly. This aspect ratio was applied to the bi-cell PZTmag-PEMFC stack and yielded a maximum net power flux of 0.1925 W·cm −2 , 20% higher than that reported in a previous study , with 68% and 76% less volume and weight, respectively.

Previous studies demonstrated a piezoelectric proton exchange membrane fuel cell (PZT‐PEMFC) stack design composed of three bi‐cells in series and a single bi‐cell, with a maximum net power density of 0.1608 W cm−2. The present study developed a modified bi‐cell design with lower volume and weight by using gold‐plated aluminum 6061. A groove‐designed PZT actuator enclosed with poly‐di‐methyl‐siloxane (PDMS) curing for 30 min can reduce uneven air feeding. Such an actuator can also improve the performance of both sides of a bi‐cell, with only a 0.7% difference in the open circuit voltage (OCV). The experimental results showed that the net power density of the new version of the single bi‐cell PZT‐PEMFC module was 0.1658 W cm−2.

Previous studies have shown that the pseudo-bipolar design of the bi-cell is composed of two outside anodes and two inside cathodes that share a common PZT vibrating device used to pump the airflow. The bi-cell is operated by three modes of PZT-actuating process as pump mode (Pc > Pout > Pin), supply mode (Pout > Pin > Pc), and transition mode (Pout > Pc > Pin). In this study, a single module of piezoelectric PEMFC honey comb composed of 6 bi-cells on each inside wall of the honey comb has been developed to deliver the net power output 7.5W. The hydrogen storage tank is located in the middle duct of one honey comb with hydrogen supply valves and pipelines. Furthermore, for the required power output, the honey comb stack can be designed as erect-stack or planar-stack by assembling different number modules. Comparing with other polygons, the stronger honey comb stack can be designed to fit in the limited space and coupled with the fuel supply system or other power output system, for example, LED lights.