Despite the rapid advances in soft robotic actuation technologies, the main energy source that powers most wearable systems remains the conventional tethered stationary air compressor that greatly limits these systems' applicability. Several portable pneumatic energy sources have been introduced; however, the limited maximum output pressure and flow rate, size and weight, large operational noise, and potential safety hazards must still be resolved before being applied to current wearable applications. In this study, we propose the design of a portable double-piston crank microcompressor that can generate up to a maximum gauge output pressure of 986 kPa and a maximum flow rate of 9.78 L/min, while maintaining a simple structure, static mass of 1.5 kg and not generating any safety hazards. The design requirements in terms of maximum pressure and flow rate were optimized based on wearable robotic applications. The sound intensity level generated by the developed microcompressor was approximately 65 dB, which can be used for long-term usage, at maximum flow rate when measured from a 0.5 m distance.