Experimental data of LCE-integrated soft everting robots
Data files
Jul 01, 2025 version files 1.16 MB
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Data_Dryad.zip
1.15 MB
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README.md
5.64 KB
Abstract
Soft everting robots move by extending, or growing, their body from the tip via eversion, enabling minimal interaction with the environment. They can traverse complex environments by changing the growth direction via integrated steering mechanisms. However, it is challenging to miniaturize existing steering mechanisms and to achieve multiple bends, while remaining fully-soft. In this work, we present an approach to create millimeter-scale, steerable, and fully-soft everting robots by functionalizing the robot skin with liquid crystal elastomer (LCE) actuators. We demonstrate the ability of small-scale (< 5 mm diameter) everting robots to achieve large bending angles (> 100◦) at multiple points along their length, and study the effects of the robot pressure and actuator temperature as control inputs. We demonstrate the potential of our approach for enabling practical applications, such as surgical procedures and inspection tasks. Our results highlight the advantages of functionalized robot skin and represent a step toward small, steerable, and fully-soft everting robots for applications in delicate and constrained environments.
Dataset DOI: 10.5061/dryad.jdfn2z3p6
Description of the data and file structure
"ForceCharacterization folder" includes the measured forces exerted by the robots to the environment. Two curved environments (60 degree and 180 degree) were tested. The data is collected through an ATI force sensor, NI DAQ, and ATIDAQFT.net software. The software was provided by the company.
- Each csv file includes measured force (N) and torque (Nm). The sampling rate was 62.5 Hz. All robots were 5 mm in diameter. "Tube" and "Vine" were pressurized at 3 psi. "LCEVine" was pressurized at 3.5 psi.
- Files that contain "Tube" in the file name contains results from 5 mm tube manually pushed into the environment.
- Files that contain "Vine" in the file name contains results from 5 mm everting robot navigating into the environment without any active steering mechanism.
- Files that contain "LCEVine" in the file name contains results from 5 mm everting robot navigating into the environment with LCE-actuated steering mechanism.
"MaterialCharacterization folder" includes the stress/strain characterization of the LCE used in this work.
- HighTemperatureLCE (units available at column headings)
- Files that contain "%%C", where %% is a number, represents the tensile test results of the LCE tested at %% Celsius. LCE strips used in these tests were 2 mm in width, 0.41 mm in thickness, and 20 mm in length. First one side of the strip was mounted onto a tensile testing machine. The temperature inside the chamber was changed to a desired temperature. When the LCE reached the steady state, the other side of the LCE was also mounted to the machine. After that, a tensile test was performed, and the force and displacements were recorded.
- "Blockedstress_HighTemp.xls" contains blocked stress test results at iso-strain condition while varying temperature. LCE strips used in these tests were 2 mm in width, 0.41 mm in thickness, and 20 mm in length. Both sides of the strip was mounted into the machine without any applied stress or strain. While recording the force data, the temperature inside the chamber was changed.
- LowTemperatureLCE (units available at column headings)
- "BlockedStress_LowTemp.csv" contains blocked stress test results at iso-strain condition while varying temperature. LCE strips used in these tests were 5.7 mm in width, 0.3 mm in thickness, and 30 mm in length. Both sides of the strip was mounted into the machine without any applied stress or strain. While recording the force data, the temperature inside the chamber was changed.
- "FreeStrain_LowTemp.xlsx" contains free strain (no load) of the LCE at different temperatures. LCE strips used in these tests were 5.7 mm in width, 0.2 mm in thickness, and 30 mm in length. One side of the LCE strip was mounted onto the machine. The temperature was changed, the length of the strip was measured after reaching its steady state.
"RobotCharacterization folder" includes all data collected with the robot, such as bending angles, heater resistances, and actuation temperatures.
- TransientResults_share.csv
- This file contains time series of 4 tracked points on the robot body while steering to capture the transient response of the robot. First two points (mass A and B, column B-E) are proximal to the bend and the last two points (mass C and D, column F-I) are distal to the bend. The difference between the vector angle (theta AB) between mass A and B, and the vector angle (theta CD) between mass C and D, which is theta AB - theta CD is the bending angle. Each point was tracked from videos by the Tracker software.
- GrowthPressure.csv
- Robots were first inverted. The pressure was slowly increased until we observed the tip growing or everting. Then, the pressure was recorded.
- HeaterResistance.csv
- Digital multimeter was used to measure the resistance (in Ohm) of the PEDOT:PSS heater used in the work.
- TemperatureOnHeater.csv
- We applied electrical power to the heater and the temperature on the heater was measured by an IR camera (FLIR).
- BendingAngleCharacterization.csv
- First pressure was applied to the robot. Then electrical power was applied to the heater which then actuated the LCE actuator. We took photos of the bent robot, and the bending angles were photographically measured.
- PressureHysteresis_StartHigh.csv
- First the robot was pressured to a high value (5 psi). Then, electrical power was applied to heater to actuate the LCE actuators. The target temperature was 65C. Then, the pressure was decreased down to 2.8 psi and then increased back to 5 psi. We took photos of the robot during the pressure modulation, and the bending angles were photographically measured.
- PressureHysteresis_StartLow.csv
- First the robot was pressured to a low value (2.8 psi). Then, electrical power was applied to heater to actuate the LCE actuators. The target temperature was 65C. Then, the pressure was increased up to 5 psi and then decreased back to 2.8 psi. We took photos of the robot during the pressure modulation, and the bending angles were photographically measured.
- TemperatureHysteresis
- First the robot was pressured to a desired value (2.64 or 4 psi). Then, electrical power was applied to heater to actuate the LCE actuators. The temperature was increased from 22 C to 65 C and then decreased back to 22 C. We took photos of the robot during the pressure modulation, and the bending angles were photographically measured.
Code/software
Google sheets can be used to access data