SynTouch’s BioTac, a groundbreaking tactile sensor mimicking human fingertip touch, set the standard for humanlike tactile sensing, paving the future of robotics, prosthetics, and various industries. However, its early development faced a significant hurdle: the “flex issue.” This challenge arose from the repeated bending of the sensor’s flexible fingers, leading to cracking of the delicate interconnects within.
The Challenge:
SynTouch aimed to create a smart prosthetic hand capable of sensing a wide range of tactile sensations, from temperature to texture. Initial designs incorporated a four-layer flex structure, showing vulnerability to the stresses of repeated finger movements. The delicate traces within the flex were prone to cracking, hindering the sensor’s reliability and functionality.
The Solution:
To address this challenge, SynTouch sought the expertise of our team at Flex Interconnect Technologies. Leveraging prior experience working with SynTouch, we meticulously analyzed the failure points within the sensor. Through careful design modifications and material selection, several key strategies were implemented to address the flex issue:
Staggered Flex Construction: By strategically offsetting the flex regions, we ensured that the critical traces remained closer to the neutral axis during bending, minimizing stress and the risk of cracking. - Optimized Material Selection: We carefully selected the appropriate laminate and coverlay materials, considering their flexibility, durability, and compatibility with the sensor’s performance requirements.
- Strategic Cutouts and Material Removal: To further reduce stress on the traces, we incorporated strategic cutouts and material removal in the flex regions, optimizing the mechanical design for flexibility.
Staggered Flex Construction: By strategically offsetting the flex regions, we ensured that the critical traces remained closer to the neutral axis during bending, minimizing stress and the risk of cracking. Impact and Lessons Learned:
By resolving the flex issue, we enabled SynTouch to develop a reliable and robust BioTac sensor. This breakthrough and collaboration paved the way for wider adoption of the technology across various applications, from advanced prosthetics to sophisticated robotic systems.
This project reinforced the critical importance of a holistic approach to interconnect design, considering factors such as:
- Design Layout
- Material Selection
- Stackup
- Mechanical Outline and Cutouts
These valuable lessons have continued to guide our approach to future projects, ensuring the development of reliable and innovative interconnect solutions for a wide range of demanding applications.