Disclosed herein is an all-in-one methodology for the fabrication and the programming of soft machines. Instead of relying on the assembly of individual parts, the disclosed approach harnesses interfacial flows in elastomers that progressively cure to robustly produce monolithic pneumatic actuators whose shape can easily be tailored to suit applications ranging from artificial muscles to grippers. Rationalized herein are the fluid mechanics at play in the assembly of the disclosed actuators and modeled herein are their subsequent morphing. This quantitative knowledge was leveraged to program these soft machines and produce complex functionalities, for example sequential motion obtained from a monotonic stimulus. It is expected that the flexibility, robustness, and predictive nature of the disclosed methodology will accelerate the proliferation of soft robotics by enabling the assembly of complex actuators, for example long, tortuous, or vascular structures, thereby paving the way towards new functionalities stemming from geometric and material nonlinearities.