Tactile sensing arrays are used to detect contacts of robotic systems with the environment. They are particularly useful for scenarios in which vision-based sensors cannot be used. Thanks to the presence of multiple sensing elements, tactile arrays also provide spatial information about the contact location. In this work, we present our series elastic tactile array to enable tactile exploration for position-controlled robot manipulators. Sixteen compliant sensing elements are arranged as a 4×4 array. This allows the position-controlled robot to explore objects via palpation. Tactile sensing was accomplished by measuring the change of the magnetic field caused by neodymium magnets embedded into the series elastic elements. We demonstrate the efficacy of our sensor with two sets of experiments involving physical interaction scenarios. Firstly, we show that the sensor can be used to differentiate between rigid and deformable objects. Secondly, we show that point clouds of objects can be generated quickly with our sensor module attached to a position-controlled robot manipulator as an end-effector.

Energy efficient compliant actuation is the missing ingredient and key enabler of next-generation autonomous systems, domestic robots, prosthetic devices, orthotic devices, and wearable exoskeletons, to name a few. For all these devices, one would wish to develop actuators enabling wide range impedance modulation with low energy cost. Using conventional and biologically-inspired compliant actuation, previous research led to functional devices but with high energy cost. Here we introduce a minimalistic compliant actuator to realize impedance modulation with low energy cost. Using this actuator we demonstrate stiffness augmentation in human-machine collaboration. We argue that the non-biologically-inspired actuation concept presented here may effectively complement a biological system, by restoring or extending its functionality, with negligible energy cost.