Soft Pneumatic Fingertip Actuator Incorporating a Dual Air Chamber to Generate Multi-Mode Simultaneous Tactile Feedback

A complete set of diverse haptic feedbacks is essential for a highly realistic and immersive virtual environment. In this sense, a multi-mode haptic interface that simultaneously generates multiple kinds of haptic signals is highly desirable. In this paper, we propose a new silicone-made pneumatically controlled fingertip actuator to render pressure and vibrotactile feedback concurrently to offer a realistic and effective haptic sensation. A new silicone-based stacked dual-layer air chamber was designed. The volume of the chambers is controlled by pneumatic valves with compressed air tanks. The top/upper air chamber renders vibration feedback, whereas the bottom/lower air chamber renders pressure feedback. The proposed silicone-made fingertip actuator is designed so that it can be easily worn at the fingertips. To demonstrate the potential of the system, a virtual environment for rendering three different types of haptic textures was implemented. Extensive performance evaluation and user studies were carried out to demonstrate the proposed actuator’s effectiveness compared to an actuator with single vibrotactile feedback.

A platform for stop flow gradient generation to investigate chemotaxis

The ability of artificial microswimmers to respond to external stimuli and the mechanistical details of their origins belong to the most disputed challenges in interdisciplinary science. Therein, the creation of chemical gradients is technically challenging, because they quickly level out due to diffusion. Inspired by pivotal stopped flow experiments in chemical kinetics, we show that microfluidics gradient generation combined with a pressure feedback loop for precisely controlling the stop of the flows, can enable us to study mechanistical details of chemotaxis of artificial Janus micromotors, based on a catalytic reaction. We find that these copper Janus particles display a chemotactic motion along the concentration gradient in both, positive and negative direction and we demonstrate the mechanical reaction of the particles to small forces deviations, explaining this behaviour.

An Interdisciplinary Collaboration to Improve Hypertension Medication Adherence for Older Adults

Hypertension is highly prevalent in older adults (74.5% in ≥60 years) with dire consequences, and adherence to hypertension medications is low (approximately 50%). With increased smartphone use among older adults (81% for 60-69 years, 62% for ≥70 years), technology innovations can improve medication adherence. This symposium highlights the efforts of an innovative interdisciplinary team of experts (clinical, cognitive aging, human factors, health technology) to develop and implement the Medication Education, Decision Support, Reminding, and Monitoring (MEDSReM) system to improve hypertension medication adherence for older adults. MEDSReM is a theory-based, integrated mobile application (app) and companion web portal that educates, supports missed dose decisions, reminds, monitors adherence, and incorporates blood pressure feedback. In this symposium, we describe the interdisciplinary development efforts. Insel et al. will present the theory-based intervention, technology translation, and advancement of the MEDSReM system. Lee et al. will describe the interdisciplinary team and describe the work by the decision support subteam that created the medication formulary and generated an algorithm to guide missed-dose decisions based on pharmacology of aging. Rogers et al. will discuss the education subteam’s development of educational information about hypertension, medications, and adherence for the MEDSReM system. Mitzner et al. will illustrate the instructional support sub-team’s efforts to ensure older adults can interact with both the smartphone app and online portal. Lastly, Hale et al. will describe the user testing subteam’s usability processes including the integration of blood pressure self-monitoring. These efforts will provide insights for other interdisciplinary teams developing technology interventions for older adults.

Research on the Correction of the Linkage Hydraulic System of the Composite Hydraulic Gripper Used in Coal Mine Rigs

The research against the defect that the gripper of the rig using a traditional linkage hydraulic system always clips back to damage drill pipes when the rig starts to rotate is presented. The correcting solution of a kinetic pressure feedback system including a damper and an accumulator is described by establishing the transfer function of the linkage system and analysing major factors making the gripper to clip back. Taking the ZYWL-4000SY automatic rig for instance, the linkage hydraulic system after correction is compared with that of before in simulating analysis and the correcting solution is verified by both lab and field tests. The results show that the corrected gripper works well without hurting pipes and the rig operates in good and stable condition. The theoretical foundation and method are provided to design and test the linkage function of the composite hydraulic gripper of other similar rigs.

Postural stability assessment in flatfoot subjects trough lyapunov exponent analysis

Background Flatfoot subjects presents an increase plantar foot area related to a plantar pressure feedback impairment. The Lyapunov Exponent is considered a nonlinear parameter used to characterize a signal chaotic behavior measuring the information rate loss from time series, i.e., for the Center of Pressure data. This exponent is used to quantify and measure the capability and resistance of subjects to several perturbations. The study purpose was to investigate the postural stability differences among foot posture condition through the Lyapunov Exponent analysis. Methods The sample of the observation descriptive study consisted of 31 participants (23.26 yo ± 4.43 SD) comprising a total of 62 feet, where 15 integrated into the experimental group with bilateral flatfoot condition and the remaining 16 in the control group with the bilateral neutral foot condition. Subjects were screened, before posture analysis, using the Navicular Drop Test and Resting Calcaneal Stance Position test, to characterize each group. All participants were subjected to a bipedal weight-bearing stance posture stability analysis a force platform, both in eyes-open and closed condition. The Lyapunov Exponent was calculated using the Matlab-R2020b (MathWorks Inc., USA) software. Results Regarding the Center of Pressure outcomes, only the Lyapunov Exponent value upon the Antero-Posterior component regarding groups in the eyes closed condition (diff = 3.09°, p = .016) presented a significant result. Conclusion Flatfoot subjects present a significant difference compared to neutral foot participants, in bipedal weight-bearing stance, in the eyes closed condition regarding the Lyapunov Exponent. This relates to increase variability and decrease stability regarding the Antero-Posterior component.

Experimental Study of the Direct Drive Hydraulic System with the Torque Mode

The torque mode is more suitable for the direct drive 6 degree of freedom (6-DOF) parallel mechanism than the speed mode that both dynamic coupling and current coupling among motors are easily solved, but its key parameters and dynamic characteristics have never been studied, which are important and are the goals of this paper. First the hydraulic system of the direct drive 6-DOF parallel mechanism is simplified. Then the transfer function of the direct drive hydraulic system with the torque mode is deduced together with that of the speed mode. Finally, comparative experiments are conducted. Results show that the dynamic characteristics of the system with the torque mode which are generally worse than those with the speed mode, are mainly determined by the parameters of the motor-pump second-order element of the transfer function composed of two under-damped second-order elements, proportion differentiation (PD) control strategy and dynamic pressure feedback (DPF) control strategy are useful for the system with the torque mode, but practical and effective methods are still needed.