Methods, systems, and devices are disclosed for improved piezoelectric actuators in applications such as fuel injectors. An assembly of thin sheets may be tape cast and co-fired in piezoelectric (PZT) layers and spaced between thin sheets or one or more plated layers of electrical conductors or electrodes. The electrical conductors or electrodes may be isolated in at least two circuits by insulators and provided in integrated stacks along with instrumentation components and data transfer filaments. An assembly of stacked layers may produce motion upon actuation by application of a suitable electrical potential is adaptively operated to overcome infidelity due to vibration, thermal expansion or contraction and to produce controlled actuation motion proportional to the applied electrical potential.