The emergence of the field of soft robotics has led to an interest in suction cups as auxiliary structures on soft continuum arms to support the execution of manipulation tasks. This application poses demanding requirements on suction cups with respect to sensorization, adhesion under non-ideal contact conditions, and integration into fully soft systems. The octopus can serve as an important source of inspiration for addressing these challenges. This review aims to accelerate research in octopus-inspired suction cups by providing a detailed analysis of the octopus sucker, determining meaningful performance metrics for suction cups on the basis of this analysis, and evaluating the state-of-the-art in suction cups according to these performance metrics. In total, 47 records describing suction cups are found, classified according to the deployed actuation method, and evaluated on performance metrics reflecting the level of sensorization, adhesion, and integration. Despite significant advances in recent years, the octopus sucker outperforms all suction cups on all performance metrics. The realization of high resolution tactile sensing in suction cups and the integration of such sensorized suction cups in soft continuum structures are identified as two major hurdles toward the realization of octopus-inspired manipulation strategies in soft continuum robot arms.

Enhancing engagement of patients during stroke rehabilitation exercises are in the focus of current research. Various methods and computer supported tools have been developed for this purpose, which try to avoid mundane exercising that is prone to become a routine or even boring for the patients and leads to ineffective training. This paper introduces an engagement enhancing cyber-physical stroke rehabilitation system (CP-SRS) aiming at enhancing the patient's engagement during rehabilitation training exercises. This paper focuses on introducing the implementation and validation of the engagement monitoring subsystem (EMS) in the CP-SRS. The EMS is expected to evaluate the patient's actual engagement levels in motor, perceptive, cognitive and emotional aspects. Experiments in these four aspects were conducted separately, in order to characterize the range and accuracy of the engagement indicators by influencing the subjects into different engaged states. During the experiments, different setups were created to mimic the situations in which the subject was engaged or not engaged. The subjects involved in the experiments were healthy subjects. Results showed that the measurement in motor, perceptive, cognitive, and emotional aspects can represent the corresponding engagement level. More experiments will be conducted in the future to validate the efficiency of the CP-SRS in enhancing the engagement with stroke patients.

Implementation of tangible virtuality means providing means for creating airborne visual images, rendering them with physical properties and making them sensible for the human senses. Airborne creation and direct manipulation requires separating the virtual objects from the image generating (physical rendering) device. One step in this direction is using electroholographic, or pseudo-electroholographic, devices which are able to create virtual objects in mid-air by various light interference techniques. A virtual object is a computer model, visualized by the projection system to appear as a real, tangible object. Te enable the required direct interaction with the virtual objects these have to be perceptually separated from the projected device, they have to be perceived as floating in the air. In our research we use the Holovizio Hv128WD system, a mono-parallax, high resolution holographic imaging device supporting 3D image visualization rather than physical rendering of virtual objects. The device generates 62 views of virtual objects where each view is visible from a specific viewing direction. The user of the system perceives this as a stereo view to the object. We have been collecting application experiences related to this device for more than one year, and we have found some restrictions and limitations in the image creating capabilities which we are trying to eliminate in our current research. This paper reports on the first phase of research which focuses on some major image generation problems and exploration of possible hardware, software or data management causes. The goal of this first phase is to develop and validate the proper measurement methods. A pilot experiment is performed to verify the applicability of the method. The results show that the proposed measurement methods are feasible and helpful in analyzing the observed problems. Some problems appear to have a more fundamental cause and may only be worked around.