Embedded Files
Overview of Design
Overview of Design
The final design is comprised of the following components, surrounded by stuffing and sewn into a sloth stuffed animal.
Hug Button
Actuators
Release System
Pneumatic System Schematic
Pneumatic System Schematic
Electronics
Electronics
Low-pass filter
Smooths signal to motor
Removes unwanted noise and vibration
Increased longevity of motor
Components
Components
Hug Button
Hug Button
Activates snap action switch for interactive play experience.
Incorporates 3D printed hinge for seamless integration.
Durable and lightweight from 3D Printed PLA Material
Snap Action Switch (Honeywell V7-1C17D8-263 )
Advantages:
Offers tactile feedback when actuated.
Snap-action mechanism ensures consistent performance.
Resistant to vibration and shock.
Designed for high-speed, repetitive switching.
Provides audible click for user feedback.
Actuators
Actuators
The actuators were made up of two layers. The bottom layer is called the strain limiting layer, which was made out of denim, a material that does not expand. The top layer is called the stretch layer, which is made out of a fabric that can stretch in one direction. Therefore, when the balloon is inflated, the air pressure causes the top layer of fabric to stretch. This creates a bending motion. For our design, we made the top layer wider by 1 cm in all directions and included 0.5 cm pleating.
Strain Limiting Layer
Stretch Layer
Inside of this fabric lining is a balloon made out of thermoplastic polyurethane (TPU) which is 1.75 times wider than the fabric sleeve. This reduces risk of fatigue because there is less pressure on the seam of the plastic balloon.
Video Demonstration
Video Demonstration
IMG-7472.mov
Look at that curl!
Look at that curl!
Release System
Release System
Solenoid Valve
Smaller than mechanical release valves
Not coupled to release button (can be anywhere inside toy)
No force required to actuate
Check Valve
Ensures system pressure remains above 51 kPa (7.5 PSI)
Reduces time needed to actuate arms
Usage
Usage
The user will provoke actuation by hugging the toy, setting off the micro-switch in the hug button.
This will turn on the electric pump and inflate the actuators in the arms to curl around the shoulders of the user. Once a pressure of 70 kPa is attained within the actuators, the pressure switch will turn off the pump.
The hug can be released by holding down button on the foot, which releases air, decreasing pressure down to 50 kPa.
Performance Summary
Performance Summary
Video Demonstration
Video Demonstration
MAH01418_MP4_AdobeExpress (1).mp4Actuator Performance
Actuator Performance
Target bending angle calculated from average 9 year old child shoulder measurements.
Initial tubing actuator unable to sustain pressure above 20 kPa due to severe leakage
Final knit-textile actuator achieves desired angle at 50 kPa, and behaves linearly with increased pressure.
Comparison of Results to Initial Performance Requirements
Comparison of Results to Initial Performance Requirements
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