Designing miniaturized robots and bioelectronic devices will enable access throughout the entire human body, leading to novel procedures at the cellular level and offering localized diagnosis and treatment with unprecedented precision and efficiency. However, the soft, complex, and multi-dimensional nature of biological systems poses significant challenges for mechanical design, manufacturing, materials engineering, and functional integration in miniaturized devices. My research focuses on developing miniaturized robots and probes that seamlessly interface with and precisely interact with biological systems. By leveraging precision 3D nanomanufacturing, novel biomaterials, and emerging biophysical principles, we aim to engineer functional microrobots and bioelectronic devices to deepen physiological understanding, enable predictive diagnostics, and advance precision therapeutics. In this talk, I will first provide an overview of the challenges and design rationales behind micro/nanorobotics and mechanically compliant bioelectronics, followed by highlights of a few recent advances from my lab, inspired by biological systems or driven by biomedical problems. These include 3D-printed microrobots capable of magnetic actuation, imaging, and magnetothermal hyperthermia; hyperelastic microrobots with extreme deformability for navigating complex physiological constraints; adaptive, skin-conformal soft microelectrode arrays for high-fidelity electromyography recordings and robotic control; and microfabricated neural probe arrays for brain-wide neural circuit interrogation. These miniaturized robots and probes will enable unprecedented interactions across biological, physical, and virtual domains, driving the next generation of precision healthcare.