In this study, a flexible tactile sensing array based on a capacitive mechanism was designed, fabricated, and characterized for sensitive robot skin. A device with 8 × 8 sensing units was composed of top and bottom flexible polyethyleneterephthalate (PET) substrates with copper (Cu) electrodes, a polydimethylsiloxane (PDMS) dielectric layer, and a bump contact layer. Four types of microstructures (i.e., pyramids and V-shape grooves) atop a PDMS dielectric layer were well-designed and fabricated to enhance tactile sensitivity. The optimal sensing unit achieved a high sensitivity of 35.9%/N in a force range of 0–1 N. By incorporating a tactile feedback control system, the flexible sensing array as the sensitive skin of a robotic manipulator demonstrated a potential capability of robotic obstacle avoidance.

This paper presents the design, fabrication, and characterization of a self-powered energy harvesting system in intermittent working mode. The system consists of an electromagnetic energy harvesting device, a self-driven power management circuit (PMC) and an electronic load. The harvesting device with nonlinear magnetic-spring configuration converts vibration energy into electrical energy from low-frequency hand shaking of human being. The PMC is able to regulate, store the generated energy, and smart control the powering of the electronic load without any external voltage supply. The self-powered energy harvesting system is constructed especially for the circumstance that the power generation is insufficient to directly power-up the load. Future potential application could be self-powered microelectronics and wireless sensor nodes. Index Terms-Self-powered energy harvesting system, low-frequency vibration, self-driven power management circuit. I. INTRODUCTION R ECENT advances in microelectronic devices with ultra-low power consumption have stimulated the growing interest of energy harvesting technology [1]-[3]. As the use of conventional batteries has a limited lifetime and may fail at inconvenient time. For example, the autonomous sensor nodes [4] used in the field of environmental monitoring or structure safety detection are numerous and extensively distributed, the replacement of batteries requires plenty of manpower and resources. Energy harvesting technology [5]-[7] could be a promising alternative for reducing the maintenance cost and chemical waste of battery. Kinetic energy is attractive for the miniature energy harvesting devices, as it exists in a variety of scenarios, such as structural or machines vibrations, and human motions [3]. The devices generate electrical power based on

Advances in flexible and multifunctional electronic devices have enabled the realization of sophisticated skin for robotics applications. In this paper, a large-scale, flexible and self-powered tactile sensing array (TSA) for sensitive robot skin is demonstrated based on the triboelectric effect. The device, with 4 × 4 sensing units, was composed of a top triboelectric polyethylene terephthalate (PET) layer, a bottom triboelectric copper (Cu) layer and a bottom PET substrate. A low-cost roll-to-roll ultraviolet embossing fabrication process was induced to pattern the large-scale top PET film with microstructures for high-output performance. The working mechanism and output performance of the triboelectric TSA were demonstrated and characterized, exhibiting good stability and high sensitivity. By integrating a tactile feedback system, the large-scale TSA, acting as intelligent skin for an industrial robot, was able to realize emergency avoidance and safety stop for various unknown obstacles under various working conditions. The system also has good real-time performance. By using a large-scale roll-to-roll fabrication method, this work pushes forward a significant step to self-powered triboelectric TSA and its potential applications in intelligent robot skin.

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