Soft-Robotics and Robotic Hand

Soft-Robotics and Robotic Hand

1. CRITERIAL OF ARTIFICIAL FINGER

   • Natural motion
   • Antropomorphic feature
   • Non-pre shapling-linear
   • pre shapling-angular
   • Shape adaptative
     • shape adaptive hand
       • Reduce the number of actuators, so the fingers can move together
     • shape adaptive fingers
       • Reduce the number of actuators, so the fingers can move together
   • Pinching motion
     • This type of grasp is the coordination of the index finger and thumb to hold an object.
     • The finger rotate and the distal phalange only perform a translation motion
   • Stability
     • The prosthesis stable, to reach this condition, each finger is in static equilibrium, that means the contact forces must be zeros or positive.
   • Workspace
     • Depends on the number and length of the phalanges and their range of motion.
   • Physical characteristics
     • Weight
       • The Number of phalanges, type of mechanism, geometric dimension and the material affect a finger’s weight. Shape-adaptive mechanisms are heavier than non-shape-adaptive.
     • Number of phalanges
       • Most commercial are developed by one or two phalanges.
     • Compactness
       • It is ideal to develop a finger as compact as the human finger

2. Soft robotics

   • inspired by nature, is an emerging field in which flexible and compliant materials are implemented in various robotic systems.
     • ACTUATORS
       • SM Alloys (NiTi)
       • SM polymers
       • Fluidic elastomer actuator
         • Soft elastomer layers • Relatively inextensible constraint
       • Pneumatic artificial muscle
         • McKibben actuator • Inflatable elastic tube – braided mesh
       • Possible motion
         • • Primitive type • Extending, contracting, twisting, bending
     • SENSORS
       • Zero damage
       • Feedback
       • Control of actuator
       • Minimum physical influence
       • Minimum physical influence
       • Durable

3. 3D printing can deliver parts of very sophisticated

   • 3D printing is a technology that offers increased ‘design freedom’ and allows designers and engineers to create unique products
   • Hydrogels can bear pressures from kilopascals to megapascals
   • A soft robotic glove with soft actuators inside it was recently developed through 3D printing and can be helpful in moving human fingers
   • Relation between 3d printing & soft robots
     • Shape morphing materials with photosensitivity, thermal activation and responsive to water can also be printed now a days through 3D printing technology.
     • Such soft robots can take part in rescue operations or used for the applications of collecting sensor data from dangerous environments
     • Researchers have also managed to develop a soft robotic hand through 3D printing technology with the ability feel surfaces like the natural hand of human beings.
   • Smart materials: Observable change in response to external stimuli
     • Thermal Chemical Mechanical Optical Moisture pH Pneumatic Electric Magnetic

4. Replicating natural bidirectional communication between the nervous system and the human hand is undoable

   • It has 34 muscles; which lead to srenght and precise movements of the fingers
   • It is connected to de CNS for actuation and somatosensory feedback
   • Biosignal Acquisition
   • Control architecture
   • Feedback interface

5. Enabling a prosthetic hand to replicate all the functions of a human hand is almost impossible

   • Force information and tactile feedback help prevent slippage and detect rigidity of the gripped object.
     • The integration of sensory information with automatic control helps to generate a functionally rapid adaptive response within the prosthesis.
     • Makes the user feel more natural, enhancing a stable grip.
     • Making hand prostheses more adaptable and integrable to mitigate the cognitive burden of the user.