DOI: 10.5061/dryad.jdfn2z3p6
title: Experimental data of LCE-integrated soft everting robots

description: 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 (&lt; 5 mm
 diameter) everting robots to achieve large bending angles (&gt; 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.
description: # Experimental data of LCE-integrated soft everting robots Dataset DOI:
 [10.5061/dryad.jdfn2z3p6](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