Short answer

Incorporate hybrid rigid-flexible joint designs in prosthetic fingers to achieve a more natural range of motion and adaptive grasping capabilities.

Field: Human Factors
Source: Sensors (2025)
Method: Experimental validation and functional prototyping
Evidence: Strong effect

A novel rigid-flexible coupled finger mechanism with a 1-active-1-passive joint configuration can significantly improve the dexterity of prosthetic hands, enabling more human-like grasping and manipulation of objects. This human factors research insight is drawn from a 2025 study published in Sensors. Using Experimental validation and functional prototyping, researchers explored how this design variable affects real-world outcomes. The key design takeaway: Incorporate hybrid rigid-flexible joint designs in prosthetic fingers to achieve a more natural range of motion and adaptive grasping capabilities.

Study

Human FactorsNew This WeekStrong effect

Rigid-Flexible Coupling Enhances Prosthetic Hand Dexterity for Adaptive Grasping

Sensors · 2025

Key Findings

01The rigid-flexible coupled finger mechanism with a 1-active-1-passive joint configuration successfully mimics human-like workspace and dexterity.
02The prosthetic hand demonstrated stable grasping of flexible objects of various shapes and sizes.
03The integration of electromyography (EMG) with a TCN algorithm allowed for improved mapping of user intent to grasping force.

Application

Design takeaway

Incorporate hybrid rigid-flexible joint designs in prosthetic fingers to achieve a more natural range of motion and adaptive grasping capabilities.

How to apply

When designing robotic grippers or prosthetic hands, consider combining rigid structural elements with flexible compliant materials or passive joints to allow for more nuanced and adaptive interactions with objects.

Project actions

01Consider how different materials (rigid vs. flexible) can be combined in a single component to achieve desired movement characteristics.
02Explore how passive joints can complement active actuators to increase the overall dexterity of a mechanism.

Method & Evidence

AimHow can a rigid-flexible coupled finger mechanism with a 1-active-1-passive joint configuration enhance the dexterity and adaptive grasping capabilities of a multi-degree-of-freedom prosthetic hand?

MethodExperimental validation and functional prototyping

ProcedureA prosthetic hand prototype was designed and fabricated with a novel rigid-flexible coupled finger mechanism. This prototype was then subjected to a series of experiments involving adaptive grasping and handheld manipulation tasks to evaluate its performance, particularly in grasping flexible objects.

ContextProsthetic device design and human-robot interaction

Variables

IVRigid-flexible coupled finger mechanism (vs. traditional rigid mechanisms)

DVDexterity, adaptive grasping capability, stability of grip on flexible objects

CVNumber of fingers, number of actuated joints, control algorithm (TCN for EMG mapping)

Strengths & Limitations

Strengths

+Novel mechanical design for enhanced dexterity.
+Demonstrated practical application in adaptive grasping of flexible objects.

Limitations

The study's findings might be specific to the materials and actuator types used; generalizability to all prosthetic designs needs further investigation. The complexity of manufacturing and potential cost implications of such hybrid structures are not fully explored.

Reliability & validity

The study's validity is supported by experimental validation and functional prototyping. Reliability could be further enhanced by repeating trials with multiple prototypes and under varied conditions.

Think critically

To what extent does the 'passive' joint in the rigid-flexible coupling truly operate independently, and how might its behaviour be influenced by the active joint and external forces, potentially leading to unintended movements?

Design Principles

"Hybrid rigid-flexible actuation in robotic end-effectors can enhance dexterity and adaptability for complex manipulation tasks."

For users of prosthetic devices, enhanced dexterity directly translates to improved functional independence and a more natural interaction with their environment. This design approach offers a pathway to creating prosthetics that are not only functional but also more intuitive and comfortable to use.

What This Means for Your Design

This research shows that by using a mix of stiff and bendy parts in the fingers of a prosthetic hand, it can move more like a real hand and grip things, even soft ones, more reliably.

How to use in your project

1.Reference this study when discussing the mechanical design of your prosthetic or robotic hand, particularly the benefits of hybrid actuation for dexterity and adaptive grasping.

Add to My Project

Quick Cite

Paragraph starter

The development of a novel rigid-flexible coupled finger mechanism, as demonstrated in this research, offers a significant advancement in prosthetic hand design. By integrating passive joints with active actuation, the mechanism achieves enhanced dexterity and a more anthropomorphic workspace, enabling stable adaptive grasping of diverse objects, including flexible ones. This approach provides a practical solution for improving the functional capabilities of prosthetic devices.

Source

Sensors

An Adaptive Grasping Multi-Degree-of-Freedom Prosthetic Hand with a Rigid–Flexible Coupling Structure

journal · 2025

View source

Questions About This Research

What does the research say about rigid-flexible coupling enhances prosthetic hand dexterity for adaptive grasping?: Incorporate hybrid rigid-flexible joint designs in prosthetic fingers to achieve a more natural range of motion and adaptive grasping capabilities. Evidence: Sensors (2025).
Why does "Rigid-Flexible Coupling Enhances Prosthetic Hand Dexterity for Adaptive Grasping" matter for design?: For users of prosthetic devices, enhanced dexterity directly translates to improved functional independence and a more natural interaction with their environment. This design approach offers a pathway to creating prosthetics that are not only functional but also more intuitive and comfortable to use.
How can designers apply this research?: Incorporate hybrid rigid-flexible joint designs in prosthetic fingers to achieve a more natural range of motion and adaptive grasping capabilities.
What were the main findings?: The rigid-flexible coupled finger mechanism with a 1-active-1-passive joint configuration successfully mimics human-like workspace and dexterity.. The prosthetic hand demonstrated stable grasping of flexible objects of various shapes and sizes.. The integration of electromyography (EMG) with a TCN algorithm allowed for improved mapping of user intent to grasping force.
What research method was used?: Experimental validation and functional prototyping.
How strong is the evidence?: Evidence strength is rated Strong effect, based on a 2025 journal from Sensors.
What should I do differently in my next project?: When designing robotic grippers or prosthetic hands, consider combining rigid structural elements with flexible compliant materials or passive joints to allow for more nuanced and adaptive interactions with objects.
What are the limitations?: The study focused on a specific type of flexible object grasping; further testing with a wider range of object properties and environmental conditions may be needed. The long-term durability and user comfort of the rigid-flexible coupling mechanism were not extensively detailed.