This paper proposes Spinning Sensors middleware that realizes a robotic sensor node mechanism comprised of a sensor node and a robotic actuator node such as a motor or a mobile robot. We can increase sensing space, time, and accuracy of a sensor node by attaching them onto robotic actuators. To realize a robotic sensor node, we need to achieve collaborative utilization of arbitrary sensors and actuators, and automated calculation of sensing area and time. We stated these problems as spontaneous coordination problem and sensing area calculation problem. The Spinning Sensors middleware provides the mechanism of device coordination, data processing, and management of spatiotemporal model of robotic sensor nodes. In this paper, we discuss a robotic sensor node model, and design and implementation of the middleware. We introduce three kinds of applications using the middleware such as environment monitoring, sensor controlled robot, and context-aware service. The experiments using the robotic sensor node and the middleware are conducted to evaluate and measure the possibility, performance, and practicality of a robotic sensor node mechanism.