Control over the microscopic world, at the scale of the smallest organisms, depends on the development of robots and machines that can operate at micro-nanoscales. However, fundamental limitations in the efficient miniaturization of macro-scale robotic technologies require bioinspired/hybrid approaches for actuation, sensing, and control of microrobots. Recent advances in materials, fabrication and actuation technologies have enabled the realization of wireless microrobots powered by external fields, biological organisms, and catalytic reactions. In the first part of this talk, I will introduce cell-sized (<10 µm) surface-rolling multifunctional microrobots, inspired by leukocytes in the circulatory system, actuated by external magnetic fields. Microrollers generate unprecedented strong propulsion (up to 100 body lengths per second) enabling their upstream navigation in physiological blood flow and their functionalization with targeting agents and drug molecules allows targeted, on-demand drug delivery to desired cells. In the second part, I will present reprogrammable shape morphing of small-scale magnetic soft machines enabled by heat-assisted high-resolution (<40 µm), discrete, and 3D magnetic encoding. Heat-assisted magnetic programming allows experimental optimization of the functional behavior of small-scale soft systems, including reconfigurable mechanical behavior of an auxetic metamaterial structure, tunable locomotion of a surface-walking soft robot, and adaptive grasping of a soft gripper. I will conclude the talk with a stimulating discussion on a path forward toward bio-integrated robotics at cellular and tissue scales for healthcare applications beyond targeted therapeutic delivery.