Robots have taken the place of human operators in hazardous and challenging jobs requiring high dexterity in manipulation, and robots with skin for force and tactile sensing that mimics the function of mechanoreception in animals will be highly dexterous in performing complex tasks. In this study, we propose the design of modular robotic skin, capable of detecting the magnitude and the location of a contact force simultaneously. Each skin module needs three degrees of freedom in sensing in order to estimate the horizontal and the vertical locations of the contact force as well as its magnitude. Force sensing in the proposed skin is enabled by a custom-designed triangular beam structure underneath the skin cover. A force applied to the skin cover causes the bending of the beam, which is detected by fiber optic strain sensors. The result shows the resolutions of 1.45 N for force estimation and 1.85 mm and 1.91 mm for contact localization in horizontal and vertical directions, respectively. We also demonstrate how the proposed skin can be used for remote and autonomous control of commercial robotic arms equipped with an array of the skin modules.

This study validates the effectiveness of a recently developed parallel-actuated shoulder exoskeleton robot for the purpose of characterizing the neuromuscular properties of the human shoulder joint. In particular, shoulder mechanical impedance was quantified, which can be represented by a 2ndorder system consisting of spring, damper and inertia. The shoulder exoskeleton robot, which utilizes a new type of 4-bar spherical parallel manipulator (4B-SPM), has inherently low inertia and as a result can provide fast perturbations that are often essential for characterizing neuromuscular properties. The robot was first evaluated by using a physical shoulder mockup with adjustable and known spring and mass properties. The results of the mockup test confirmed the reliability of the robot for the characterization of the mockup properties. Stiffness of the tested springs was accurately quantified with an error of less than 1.6 Nm/rad in any of the tested conditions. A pilot study with 5 human subjects further confirmed that the robot could be successfully used to quantify multi-dimensional human shoulder impedance in both pitch and yaw directions with high reliability (R2> 0.97). The average human shoulder stiffness and damping at around the neutral arm posture under low muscle activation (< 5% maximum voluntary contraction) were 30.9 Nm/rad and 3.0 Nms/rad, respectively.

In this paper, the design of a high precision device using a Linear Delta manipulator was proposed to compensate for the tremor signal in three translational directions. A Linear Delta manipulator is a suitable tremor suppression device due to the simple structure and high stiffness with the vertical direction in the application of micro manipulation such as microsurgery and cell manipulation. In order to implement the mechanism of the Linear Delta manipulator to the device, three voice coil motors and three linear encoders with high resolution were used. The flexure mechanism was applied to the device to avoid the friction effect of the small ball joint. Finally, the experiments for the validation of the proposed device were performed as follows: (1) position control in each axis for accuracy, and (2) sine wave tracking (500 μm, 12Hz) for bandwidth of the system.

Microinjection is the highly efficient delivery method of exogenous materials into cells, and it has been widely used in biomedical research areas such as transgenics and genomics. However, this direct injection task is time consuming and laborious, resulting in low throughput and poor reproducibility. This paper describes a telerobotic shared control (TSC) framework for the microinjection with high manipulation efficiencies, in which a micromanipulator is controlled by the shared motion commands of both the human operator (direct manipulation) and the autonomous controller. To determine the optimal gains between the operator and the controller, we proposed a quantitative evaluation method using Fitts' and steering laws. The results showed that a 40%-60% weighting on the human operator produced better performance for both speed and accuracy of task completion, and suggested that some level of automation or human involvement is important for microinjection tasks.