This paper proposes a novel object handling device for a robot, in which a conventional vacuum suction cup is equipped with a force sensing ability by coating its surface with a conductive thin-film polymer, poly (3,4-ethylenedioxythiophene) (PEDOT). It can detect the applied force by measuring the resistance change of the coated conductive thin film. The feature of our study is that the suction cup can work, not only as a grasping tool, but also as a force sensor. PEDOT thin film was prepared using the dip-coating method, which can coat thin film directly on a three dimensional surface. We fabricated the sensing suction cup and evaluated its sensing ability by measuring the signal-to-noise ratio, sensitivity, reliability, and frequency response. The resistance changed linearly with respect to the applied force, showing the device's applicability as a force sensor for a vacuum-type robotic hand. Grasping tests for an inclined object, a misaligned object, and an undulated surface were conducted using two or four sensing suction cups attached to the end of the robot. All suction cups showed positive results and the robot successfully picked up the object in each scenario.

A novel capacitive tactile sensor using a polyurethane thin film is proposed in this paper. In previous studies, capacitive tactile sensors generally had an air gap between two electrodes in order to enhance the sensitivity. In this study, there is only polyurethane thin film and no air gap between the electrodes. The sensitivity of this sensor is higher than the previous capacitive tactile sensors because the polyurethane is a fairly flexible elastomer and the film is very thin (about 1 µm). The polyurethane film is formed by spin-coating and etched back from 6 µm to 1 µm using 48% sulfuric acid. As a result of evaluation, the sensitivity of the developed sensor (diameter is 1 mm) is 1.3 pF/Pa (800 pF/N considering the sensing area). Young’s modulus of the thin polyurethane film was estimated to be 20 kPa.

A cantilever‐type vibration energy harvester (VEH) made of PolyVinylidene DiFluoride (PVDF) was fabricated and characterised. PVDF is one of polymer piezoelectric material, which is more flexible than ceramic‐based piezoelectric materials such as lead zirconate titanate. Since PVDF dissolves in organic solvent, it is coatable on substrate or parts, making it compatible with micro electro mechanical systems process. The fabrication process of VEH is as follows: a PVDF film (thickness: 30 µm) was coated on a phosphor bronze rectangular plate (length: 35 mm, width: 15 mm, thickness: 0.1 mm) by bar‐coating method, followed by polarisation by corona discharge method. Aluminium top electrode (length: 30 mm, width: 10 mm, thickness: 0.3 μm) was deposited on the PVDF film by DC sputtering. One end of the plate was clamped by a fixture to form a cantilever, the length of which is 25 mm. Finally, a proof mass ( m = 0.2 g) was attached to the free end of cantilever. Output power P at resonant frequency (= 55 Hz) was measured as a function of load resistance R , in which acceleration was set to 17 m/s ² . Maximum output of 4.3 µW was achieved at R = 2.1 MΩ, which is not inferior to those of reported VEHs using ceramic piezoelectric materials.

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We propose a concept of a flexible sensor array using a novel capacitive force sensor not having a vulnerable electrode on the force applied site. It has a polymer domed structure inside which silicone oil is contained. When the force is applied, the oil is pushed into the surrounding thin channels, where the change in capacitance due to the inflowing dielectric oil is measured between two electrodes on the top and bottom surfaces of the channel. Since the channel does not have a directly applied external force to it, the electrodes do not suffer from damage problems. The change in capacitance was simulated using a simplified flow model. The first trial device of the sensing element has been fabricated. A sensitivity of 0.05 pF/gf was achieved.