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We introduce MechSense, 3D-printed rotary encoders that can be fabricated in one pass alongside rotational mechanisms, and report on their angular position, direction of rotation, and speed. MechSense encoders utilize capacitive sensing by integrating a floating capacitor into the rotating element and three capacitive sensor patches in the stationary part of the mechanism. Unlike existing rotary encoders, MechSense does not require manual assembly but can be seamlessly integrated during design and fabrication. Our MechSense editor allows users to integrate the encoder with a rotating mechanism and exports files for 3D-printing. We contribute a sensor topology and a computational model that can compensate for print deviations. Our technical evaluation shows that MechSense can detect the angular position (mean error: 1.4°) across multiple prints and rotations, different spacing between sensor patches, and different sizes of sensors. We demonstrate MechSense through three application examples on 3D-printed tools, tangible UIs, and gearboxes. 

Textile pneumatic actuators were developed to provide full assistance to lift the arm of a model of an 11-year-old male beyond 120 degrees of shoulder abduction. Two fabrics and a variety of sealing techniques, methods of attachment, and actuator shapes were comparatively evaluated using textile and functional tests. The results identified that both fabrics and one of the three sealing techniques were effective for creating air-tight, functional actuators. Actuators were more effective when the bands attaching them were closer to the axilla. Rectangular and wing-shaped actuators, both lifting the model of an 11-year-old male’s arm above 120 degrees of abduction, were more effective than Y-shaped actuators. Multiple designs and materials may be acceptable for building textile pneumatic actuators to lift the full weight of a child’s arm. Compared to traditional hard robots, soft assistive robots offer key potential benefits related to comfort, aesthetics, weight, bulk, and cost. 

Many children have an upper extremity disability leaving them unable to explore the environment around them. Hard exoskeletons can provide support to lift a child’s arms up against gravity, but these devices are generally large and obtrusive leading to low adherence. Children often prefer to have limited arm function rather than wearing such a device. Our lab has previously designed a passive soft exoskeleton to lift children’s arms, but this did not allow for user control and was limited in the length and weight of arm it could support. Building off of this research, we have created the preliminary design for a user-controlled pneumatic soft exoskeleton that may allow users to independently raise and lower their arms.