DOI: 10.5061/dryad.jsxksn0mt
title: Data from: Active learning design: Modeling force output for axisymmetric soft pneumatic actuators

description: Soft pneumatic actuators (SPA) made from elastomeric materials can provide
 large strain and large force. The behavior of locally strain-restricted
 hyperelastic materials under inflation has been investigated thoroughly
 for shape reconfiguration, but requires further investigation for
 trajectories involving external force. In this work, we model
 force-pressure-height relationships for a concentrically strain-limited
 class of soft pneumatic actuators and demonstrate the use of this model to
 design SPA response for object lifting. We predict relationships under
 different loadings by solving energy minimization equations and verify
 this theory by using an automated test rig to collect rich data for n = 22
 Ecoflex 00-30 membranes. We collect data using an active learning pipeline
 to efficiently model the design space. We show that this learned model
 outperforms the theory-based model and a naive regression. We use our
 model to optimize membrane design for different lift tasks and compare
 this performance to other designs. These contributions represent a step
 towards understanding the natural response for this class of actuator and
 embodying intelligent lifts in a single-pressure input actuator system.
description: # Data from: Active learning design: Modeling force output for
 axisymmetric soft pneumatic actuators Dataset DOI:
 [10.5061/dryad.jsxksn0mt](10.5061/dryad.jsxksn0mt) Publication
 DOI: [10.1109/LRA.2025.3605089](https://doi.org/10.1109/LRA.2025.3605089)
 Downloading the dataset: Simply click each .zip folder (the folder, not
 the check box) individually to download the characterization data, test
 data, and ReadMe. ## Description of the data and file structure
 Characterization data contains folders of .csv and .mp4 data. The folders
 are titled with (in order): the membrane material, the membrane thickness,
 the membrane total radius [mm], the contact area radius [mm], the test
 date (year_month_day), the curing location (A/B), and the test number.
 Many folders contain additional values designating the dimensions of
 strain limiting rings [mm]: ring1 radius, ring 1 width, ring 2 radius,
 ring 2 width. For ring measurements, 'nan' indicates the lack of
 a ring. The .csv files are named with the contact height [mm] and trial
 number. There are associated .mp4 files in the 'videos' folder
 with matching names. The mass testing folder contains similar folders of
 .csv and .mp4 data. Folder metadata is indicated in the characterization
 data. File (.csv and .mp4) names indicate mass lifted [kg] and trial
 number. In some instances, a .pkl file is included in a test folder; this
 is a combination of all .csv data from that folder into a single pandas
 dataframe. This data was collected from parametrically designed
 elastomeric membranes under pneumatic inflation on custom test platforms.
 The data is split into two sections. Force data is obtained by a
 piezoelectric loadcell and HX711 breakout board, pressure via MPRLS0025,
 distance via VL53L0X time-of-flight sensors, flow via FS2012, and contact
 via limit switches or switch input. ### Files and variables #### File:
 Membrane_Characterization.zip **Description:** * The .csv files contain
 (in order): time [ms], force [lbf], pressure [PSI], distance1 [mm],
 distance2 [mm], volumetric pneumatic flow [mL/s], and contact [binary]. -
 The .csv filenames contain (in order): contact height [mm], trial number.
 * The folder names contain (in order): membrane material [Ecoflex or
 Dragonskin], thickness [mm], outer radius [mm], contact radius [mm], test
 date [yr month day], curing station [A/B], test number, and (sometimes)
 ring data [radius1, width1, radius2, width2]. - Distance 1 is on the left
 side of the test rig, while distance 2 is on the right side. These are the
 raw distances from the sensor and need to be altered to calculate the
 distance from the membrane. A distance measurement of 999 indicates an
 error. * Contact indicates if the membrane is encroaching on the test
 setup; 0 is positive contact. - Pressure data is measured inside the
 pressure chamber and should be precise during inflation and deflation.
 #### File: Mass_Testing.zip **Description:**  * The .csv files contain (in
 order): time [ms], pressure [PSI], distance [mm], contact [binary]. - The
 .csv filenames contain (in order): mass [kg], trial number. * The folder
 names contain (in order): membrane material [Ecoflex or Dragonskin],
 thickness [mm], outer radius [mm], contact radius [mm], test date [yr
 month day], curing station [A/B], test number, and ring data [radius1,
 width1, radius2, width2]. - Contact indicates a user input and begins
 deflation; 0 is a positive user input. * Pressure data is measured
 upstream from the membrane during inflation and downstream from the
 membrane during deflation. Deflation pressure is considered more reliable
 as deflation occurs more slowly. ## Code/software .csv files and .mp4
 files should be viewable in any text editor and video viewer,
 respectively.