This paper presents a new design for pneumatic networks (pneu-nets) that enable rapid actuation in soft robotics. Traditional pneu-nets require large changes in volume to achieve full bending, which limits their speed and durability. The new design, called a "fast pneu-net" (fPN), reduces the volume change needed for actuation, allowing for faster and more reliable performance. The fPN consists of an extensible top layer and an inextensible bottom layer, with chambers that expand preferentially when pressurized, minimizing strain on the material and increasing the lifespan of the actuator. The fPN can bend from a linear shape to a quasi-circular shape in 50 milliseconds when pressurized at 345 kPa. It can operate over a million cycles without significant degradation of performance. The fPN also exhibits a new mode of actuation, where at high inflation rates, it curls upon itself with chambers at its tip inflating first. This design allows for high-speed actuation (>1 Hz) over the full range of motion, with conventional, safe methods. The fPN is more efficient than the traditional "slow pneu-net" (sPN), requiring significantly less pressure, volume, and energy for full bending, and dissipating less energy during actuation. The fPN also has a longer lifespan due to reduced strain on the material. The design was tested with various elastomers, showing that softer elastomers require less pressure but more volume to bend fully. The fPN was also shown to be capable of playing a tune on an electronic keyboard, demonstrating its ability to perform useful tasks rapidly. The fPN's ability to bend in different ways depending on the inflation rate provides opportunities for new control schemes. The study highlights the potential of fPNs for applications in soft robotics, including search-and-rescue and minimally invasive surgery. The fPN's design reduces the overall size and power consumption of the robot, making it suitable for untethered applications. The study also identifies limitations of the fPN design, such as slight bending when gravity acts on the actuator and non-uniform expansion of chambers due to snap-through instability. These findings suggest that the fPN is a promising advancement in soft robotics, offering improved speed, force, and durability compared to traditional pneu-nets.This paper presents a new design for pneumatic networks (pneu-nets) that enable rapid actuation in soft robotics. Traditional pneu-nets require large changes in volume to achieve full bending, which limits their speed and durability. The new design, called a "fast pneu-net" (fPN), reduces the volume change needed for actuation, allowing for faster and more reliable performance. The fPN consists of an extensible top layer and an inextensible bottom layer, with chambers that expand preferentially when pressurized, minimizing strain on the material and increasing the lifespan of the actuator. The fPN can bend from a linear shape to a quasi-circular shape in 50 milliseconds when pressurized at 345 kPa. It can operate over a million cycles without significant degradation of performance. The fPN also exhibits a new mode of actuation, where at high inflation rates, it curls upon itself with chambers at its tip inflating first. This design allows for high-speed actuation (>1 Hz) over the full range of motion, with conventional, safe methods. The fPN is more efficient than the traditional "slow pneu-net" (sPN), requiring significantly less pressure, volume, and energy for full bending, and dissipating less energy during actuation. The fPN also has a longer lifespan due to reduced strain on the material. The design was tested with various elastomers, showing that softer elastomers require less pressure but more volume to bend fully. The fPN was also shown to be capable of playing a tune on an electronic keyboard, demonstrating its ability to perform useful tasks rapidly. The fPN's ability to bend in different ways depending on the inflation rate provides opportunities for new control schemes. The study highlights the potential of fPNs for applications in soft robotics, including search-and-rescue and minimally invasive surgery. The fPN's design reduces the overall size and power consumption of the robot, making it suitable for untethered applications. The study also identifies limitations of the fPN design, such as slight bending when gravity acts on the actuator and non-uniform expansion of chambers due to snap-through instability. These findings suggest that the fPN is a promising advancement in soft robotics, offering improved speed, force, and durability compared to traditional pneu-nets.