In this study, we presented an optimal Electrical Impedance Tomography (EIT) drive pattern based on feature selection and model explanation, and proposed a portable EIT system for applications in human-computer interaction for gesture recognition and contact detection, which can reduce the measurement time and realize a performance trade-off between the accuracy and the time response. In our experiment, eleven hand gestures were designed to verify the proposed approach and EIT system. Compared to the traditional eight-electrode method, the optimal electrode drive pattern achieved a recognition accuracy of 97.5% with seven electrodes and the measurement time was reduced by 60%. To illustrate the universality of this method, we performed a contact detection experiment. By setting seven labels on the conductive panel and using optimal electrode drive pattern, the detection accuracy reached 100% with seven electrodes and the measurement time was reduced by 85%.

This paper proposes the design and experiment of a bioinspired wall-climbing robot with spiny arrays. Inspired by the Serica orientalis Motschulsky's tarsal system, a spiny structure is designed, and the robot's foot which has two grippers using the structure is designed. An inchworm-like gait is employed and its trajectory is planned. The robot's foot as well as the whole prototype is fabricated and tested. It is verified that the foot has remarkable adhesive ability and the robot can scale vertical and inverted rough surfaces including the ceiling.

In order to investigate the magnetic-induced friction properties of magneto-rheological elastomers, isotropic and anisotropic magneto-rheological elastomers are fabricated, tribological testing setup is built, and the friction experiment is carried out. The experimental results show that the isotropic magneto-rheological elastomer has a decreasing friction coefficient with magnetic field applied, which is also affected by particle volume fraction. The influence of magnetic field on friction coefficient of the anisotropic magneto-rheological elastomers is not monotonic. The experimental results also show that the friction coefficient of magneto-rheological elastomers decreases with the increase in load for both isotropic and anisotropic magneto-rheological elastomers in most circumstances. The volume fraction of carbonyl iron powders being around 10% is the best for magneto-rheological elastomers in tuning friction. The tunable range of friction could be as high as 25% under a magnetic field of 0.25 T. Images of the magneto-rheological elastomer interfaces show that the surface roughness is reduced by about 20.7% when a magnetic field of 0.5 T is applied. The aggregation phenomenon is observed on the surface of the magneto-rheological elastomer under a magnetic field. On the basis of three-dimensional surface topography, a preliminary model for the aggregation of micro asperities on the surface of the magneto-rheological elastomer is built to interpret the influence of the magnetic field on the tribological properties of magneto-rheological elastomers.

This paper proposes a multi-level hierarchical model for the Tokay gecko ( Gekko gecko ) adhesive system and analyses the digital behaviour of the G. gecko under macro/meso-level scale. The model describes the structures of G. gecko 's adhesive system from the nano-level spatulae to the sub-millimetre-level lamella. The G. gecko 's seta is modelled using inextensible fibril based on Euler's elastica theorem. Considering the side contact of the spatular pads of the seta on the flat and rigid substrate, the directional adhesion behaviour of the seta has been investigated. The lamella-induced attachment and detachment have been modelled to simulate the active digital hyperextension (DH) and the digital gripping (DG) phenomena. The results suggest that a tiny angular displacement within 0.25° of the lamellar proximal end is necessary in which a fast transition from attachment to detachment or vice versa is induced. The active DH helps release the torque to induce setal non-sliding detachment, while the DG helps apply torque to make the setal adhesion stable. The lamella plays a key role in saving energy during detachment to adapt to its habitat and provides another adhesive function which differs from the friction-dependent setal adhesion system controlled by the dynamic of G. gecko 's body.

Motivated by the need for underwater exoskeleton control, swimming phase monitoring is critical to adjust robotic assistance to human motions. However, harsh underwater environments bring in challenges of poor robustness and serious disturbances to the few available sensing methods leading to coarse phase segmentation. Given skeletal muscle activation for limb joint motions, this paper proposes a muscle-joint synergy method to combine muscle mechanics captured by a novel capacitive sensor with joint kinematics by traditional inertial measurements. Development of the wearable sensing system is provided with details on design, fabrication and assembly. The muscle-joint synergy model is rigorously formulated and experimentally validated with breaststroke data for the first time. Immediate applications are illustrated with discrete mode identification and continuous phase monitoring, justifying the robustness of the proposed method to various artificial intelligent algorithms and different tested subjects. This work is anticipated to be valuable to unveil the mechanism of human natural motions for human-centered robotics, sport science and rehabilitation engineering in the future.