This study uses the thermal bubble inkjet technology on the design of digital controlled micro-fuel injector. A micropulsation fuel injection system is composite by the arrays of the thermal bubble micro-fuel injectors, which could be operating in high ejection frequency and with fine fuel droplets into the intake pipe on engines by accurate control mode. The use of thermal bubble micro-fuel injector is able to reduce the air pollutions and the costs of product. Each single digital signal on the thermal bubble micro-fuel injector controls the individual atomization quality of fuel droplet. The advantages of digital control on fuel droplet atomization are active control of fuel ejection volume and optimization of combustion efficiency. This study redesigns the sizes and locations of heaters within the thermal bubble micro-fuel injector. The atomized fuel droplet volumes are controlled within 100 pl. ∼ 500 pl. Up to now, the micropulsation fuel injection engine system runs smoothly to overcome disadvantageous factors compared to the inkjet printer, such as vibration, high temperature, and different working fluid.