Soft Actuators, Smart Sensors: Innovative Sensor Allows Real-Time Monitoring of Complex Systems

Novel Dielectric Elastomer Sensor (DES) offers real-time pressure and vibration monitoring in soft fluidic actuators, allowing applications in robotics and biomedical devices

 

Fluidic Elastomer Actuators (FEAs) are lightweight and flexible systems, crucial in robotics and biomedical devices, with challenges in real-time monitoring. Researchers have developed a Dielectric Elastomer Sensor (DES) to measure pressure and vibrations in these deformable structures. This novel sensor allows efficient monitoring, enhancing actuator performance, with applications in robotics, automotive systems, and infrastructure.

 

 

 

Fluidic Elastomer Actuators (FEAs) are pressurized tubes or membranes that can be easily rearranged into complex mechanical devices. They have gained significant attention for their lightweight, flexible nature, making them ideal for robotics and biomedical devices. However, the accurate measurement of their dynamic response and rearrangement is challenging because traditional sensors, such as piezoelectric accelerometers and piezoresistive sensors, are not suitable for freeform surfaces like domed roofs or complex shapes. Their rigid metallic casings restrict large deformations and affect the FEA’s performance.

 

Additionally, the accurate measurement of dynamic responses in FEAs plays an important role in automobile designing. While designing new cars with high efficiency and safety, the measurement of vibration and static pressure on the pressurized tires with an inflatable structure are inevitable. These measurements not only reveal the performance of the car, but also their structural health.

 

Motivated by this gap in technology, a team of scientists led by Professor Naoki Hosoya from Shibaura Institute of Technology (SIT), Japan, explored Dielectric Elastomer Sensor (DES) to address this challenge. The team consisted of Mr. Haruyuki Kurata from SIT, Japan, Dr. Ardi Wiranata from the University of Gadjah Mada, Professor Shingo Maeda from the Institute of Science Tokyo, Dr. David Garcia Cava from The University of Edinburgh, and Dr. Francesco Giorgio-Serchi from The University of Edinburgh. This study, published online in Measurement, on December 30, 2024, explored how DESs can be used to measure the pressure and vibration response on soft fluidic structures. As Prof. Hosoya notes, “Our study explores how DES can be effectively implemented for real-time state estimation and control of soft fluidic actuators.”

 

To understand the working of this sensor, the team of scientists fabricated a capacitive-type DES using polydimethylsiloxane (PDMS) and carbon nanotubes. This sensor was tested to measure the vibration response of soft fluidic systems under pneumatic actuation and was capable of measuring vibrations up to 100 Hz. The device measured vibration and static pressure by capturing the change in capacitance. When the DES is subjected to an external force, leading to a deformation, the capacitance increases. The team found that DES exhibited a linear response to vibration amplitude, with its sensitivity increasing as static pressure decreased.

 

Prof. Hosoya explains, “The mass and rigidity of the conventional sensors like piezoelectric accelerometers and piezoresistive sensors strongly influence the dynamic characteristics of the underlying inflatable structures, likely hindering the nominal operation of the actuator.” Unlike piezoresistive sensors, DES is flexible and can withstand large deformative rearrangements, making them ideal for real-time monitoring of FEAs.

 

These findings highlight the potential of DES as a valuable sensing device for soft robotics and health monitoring. The ability of DES to function in complex, deformative environments allows it to set a new standard for applications in robotics, biomedical devices, and large-scale infrastructure. Prof. Hosoya mentions, “DES allows capturing fast dynamic response of”

 

Finally, Prof. Hosoya concludes, “These results indicate that lightweight, highly stretchable DESs can be conveniently used as embedded units within complex fluidic networks, aiding in monitoring of this type of actuators,.”   

Reference

Title of original paper:	Dynamic response characterization of soft fluidic actuators via dielectric elastomer sensors
Journal	Measurement
DOI:	https://doi.org/10.1016/j.measurement.2024.116616

Additional information for EurekAlert

Latest Article Publication Date:	30 December 2024
Method of Research:	Experimental study
Subject of Research:	Not Applicable
Conflicts of Interest Statement:	The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper

       

Funding Information