Robots with submillimeter dimensions are of interest for applications that range from tools for minimally invasive surgical procedures in clinical medicine to vehicles for manipulating cells/tissues in biology research. The limited classes of structures and materials that can be used in such robots, however, create challenges in achieving desired performance parameters and modes of operation. Here, we introduce approaches in manufacturing and actuation that address these constraints to enable untethered, terrestrial robots with complex, three-dimensional (3D) geometries and heterogeneous material construction. The manufacturing procedure exploits controlled mechanical buckling to create 3D multimaterial structures in layouts that range from arrays of filaments and origami constructs to biomimetic configurations and others. A balance of forces associated with a one-way shape memory alloy and the elastic resilience of an encapsulating shell provides the basis for reversible deformations of these structures. Modes of locomotion and manipulation span from bending, twisting, and expansion upon global heating to linear/curvilinear crawling, walking, turning, and jumping upon laser-induced local thermal actuation. Photonic structures such as retroreflectors and colorimetric sensing materials support simple forms of wireless monitoring and localization. These collective advances in materials, manufacturing, actuation, and sensing add to a growing body of capabilities in this emerging field of technology.

Bioengineering approaches that combine living cellular components with three-dimensional scaffolds to generate motion can be used to develop a new generation of miniature robots. Integrating on-board electronics and remote control in these biological machines will enable various applications across engineering, biology, and medicine. Here, we present hybrid bioelectronic robots equipped with battery-free and microinorganic light-emitting diodes for wireless control and real-time communication. Centimeter-scale walking robots were computationally designed and optimized to host on-board optoelectronics with independent stimulation of multiple optogenetic skeletal muscles, achieving remote command of walking, turning, plowing, and transport functions both at individual and collective levels. This work paves the way toward a class of biohybrid machines able to combine biological actuation and sensing with on-board computing.

The rapid advancement of flexible neural interfaces and devices is revolutionizing our ability to explore the neural foundations of consciousness, intelligence, and behavior. Cutting‐edge developments in materials science and system‐level integration are significantly enhancing the spatiotemporal resolution of neural signal acquisition and modulation, paving the way for next‐generation brain‐computer interfaces. These technologies enable unprecedented investigations into the causal relationships between neural dynamics and behaviors in freely moving subjects, offering new insights into various neurocognitive domains. The integration of artificial intelligence and brain organoids with neuroscience research promises to further decode complex neural signals, deepening our understanding of multilevel neural dynamics. Beyond their scientific implications, these innovations also offer transformative possibilities for the diagnosis, treatment, and management of neurological and psychiatric disorders. This perspective paper examines how flexible neural interfaces overcome the limitations of traditional neurotechnology, their potential impact on neural research, and their promising applications in treating neurological and psychiatric disorders, while also considering the ethical implications and future challenges in this rapidly evolving field.