<div xmlns="http://www.tei-c.org/ns/1.0"><p>Active force sensors are key instruments to get around the tradeoff between the sensitivity and the measurement range of conventional passive force sensors. Thanks to their quasi-infinite stiffness in closed loop, active sensors can be applied for force measurements on samples with a wide range of stiffness without interference with the mechanical parameters of the sensor. MEMS (Micro-Electro Mechanical Systems) active force sensors have been wildly developed in the literature but they are ill adapted for force measurements at the Newton level needed in meso-scale robotics. In this article, a novel structure for a meso-scale active force sensor is proposed for the measurement of forces from the milli-newton to the newton.This novel meso-scale sensor is based on a nil-stiffness guidance and an electromagnetic actuation. This paper deals with its design, identification, calibration and closed loop control. The sensor exhibits nil-stiffness characteristic in open loop and an almost infinite stiffness in closed loop. This allows measuring forces with a large range of gradients. First experiments shows the ability of this new sensor architecture to measure low frequency forces up to 0.8 N with a precision of 0.03 N and a closed loop 20 dB cutoff frequency of 73.9 Hz.</p></div>