Research was done on actuators for a soft robotic glove that could assist children with cerebral palsy with at-home hand physical therapy. Materials in the construction of fabric-based soft pneumatic actuators were evaluated for this purpose. Three different bladder types (TPE impulse sealed bladders, condoms, and modeling balloons) were tested. The straightening and bending force each actuator could produce as well as the shape the actuator formed when unrestrained were analyzed. The results indicated that condoms and modeling balloons are superior to TPE bladders
for the use as bending bladders. All bladder types performed well as straightening bladders so any could be chosen depending on the desired quantitative values such as the straightening force and force-to-pressure relationship. Further research is needed into the durability of each bladder type and into attachment methods of each bladder to prevent air leaking.
Cerebral palsy patients currently face a significant treatment gap, which in part has to do with the high cost of traditional treatment methods. Research has shown that cerebral palsy affects 1 in 323 children in the United States (CDC, 2018), 42% of which aren’t receiving the care that they need. The medical expenses needed for children with cerebral palsy are 16 times higher than other children, which could account for this high percentage. The summer research team aims to look into and develop low-cost technology alternatives that could supplement these children’s physical therapy from home. Building
upon existing work on controllable gloves with fabric actuators, my peer researchers and I looked into efficient design changes that accomplish our goal (Polygerinos, 2013).
Based on a review of research papers, existing strategies for glove position control (Yap, Kamaldin, Kim, Nasrallah, Goh, Yeow, 2015), were paired with sensors that could be integrated into a low-cost version. Two different sensor types were chosen to be evaluated for their feasibility for our project: a commercially available glove controller based on a conductive-ink bend sensor, and a novel
conductive textile. Analysis of the data demonstrated that the glove controller sensors worked well, better than the conductive textiles, as expected. The results indicate that the glove sensors worked best when bending them along a radius rather than at a joint since the signal is strongest when the sensors are bent consistently along the length rather than at a single point. Further research is needed to characterize the accuracy of the sensors, but they are ready to be integrated and tested with the other control aspects.
During a research period of June-August 2020, a team of students from the Laboratory for
Adaptation, Inclusion, and Robotics developed fabric-based pneumatic actuators for use in
at-home physical therapy for children with spastic cerebral palsy. This paper focuses on the
mechanical components of the device–specifically, what materials and productions methods
are most effective in creating a useful, affordable actuator. It details the development of
several working prototypes and what methods were used to test them, as well as what
research remains to be done on this subject in the future.