Flexible electronics has gained tremendous attention over the past decades, revolutionizing fields such as telecommunication, multimedia, and healthcare. [1] Major electronic components, e.g., interconnects, antennas, diodes, and transistors, have been fabricated on thin polymeric foils to generate new options in the toolkit of developers. Applying thin polymeric foils as substrates facilitates the production of electronic systems with low weight, shape compliance, robustness, and reliability with ever-increasing complexity. The ultrathin design of these electronic devices has promoted bioelectronics that include artificial skins, [2] sensor arrays, [3] electronic implants such as brain probes, [4] and nerve cuffs, [5] to name a few. The ability to naturally conform to complex 3D shaped anatomies is a vital feature for electronic devices to interact with soft biological tissue. And while the shape of a large-area flexible electronic device can be easily adapted manually to the geometric requirements of the final application, handling becomes increasingly more challenging when aiming at smaller dimensions, when, e.g., a submillimeter nerve fiber bundle has to be enclosed gently with a similarly small cuff implant. [6] Shapeable microelectronic devices, which transform their shape on demand, provide an alternative strategy to accomplish this challenging task. [7] For instance, soft microscale structures with integrated electronic circuits have recently been demonstrated to wrap around peripheral nerves in situ when exposed to elevated temperatures or moisture. [8,9] These devices, however, lack the ability to reshape repeatedly and on demand in the operating environment. Such functionalities require the integration of biocompatible flexible shape and position sensors together with robust microactuators, fabricated ideally by a monolithic wafer-scale process.Among a variety of small-scale actuators that are driven by pneumatic [10,11] and hydraulic [12] pressure, electric [13] and