Dataset DOI: 10.5061/dryad.sf7m0cgnq

Description of the data and file structure

This repository is for data used to generate figures in the paper "Capillary Ratchets Activated by Interfacial Flows for Versatile Torque Generation and Micro-assembly" by Li et al, published in Sciences Advances (DOI: 10.1126/sciadv.aed5495).

It has two zip files, which contain the raw data used in the main text and supplementary materials, respectively.  The folders are labelled to indicate the associated figures.

Files and variables

File: Main_Text_Data.zip

Description: data used to generate figures in the main text

• Main_Text_Data
  • Figure 2: this folder contains data used in Figure 2, where a 3D printed device is used to generate unidirectional flow. It includes the STL model of the device, the speed tracked from the floating object (the ”float”) from one cycle of motion, and the average/SD of the rotations.
    • To quantify the rotation angle of the float, we collected float rotation angles using angular tracking. Within this folder, a subfolder named "Fig.2C-speed-one cycle" is included. In this subfolder name, "speed" refers to the vertical operating speed of the device, with units of mm/min. "One cycle" indicates that the data corresponds to one complete process of the device moving upward and then downward in the vertical direction. This subfolder contains multiple Excel data files recording the float rotation angle as a function of time; the numerical values in the filenames represent the vertical operating speed of the device. A Python script included in this subfolder is provided for generating figures from the data.
    • Additionally, in the main folder, a data file named "Fig.2D-speed-mean-std.csv" is included. This file contains statistical data after the device completed 10 cycles at different operating speeds. In this dataset, device upward motion is denoted as "forward," and device downward motion is denoted as "backward." The file reports the mean and standard deviation of float rotation angles during upward and downward motions across 10 cycles at different vertical operating speeds. The folder also includes the 3D STL file of the device.
  • Figure 3: this folder contains data used in Figure 3, where the rotation of the float is size-dependent. Raw data for float rotation angle with different sizes and statistical data are provided.
    • To investigate the effect of float size on rotation, experiments were conducted using circular floats of different sizes. Within this folder, a subfolder named "Fig.3D-size" is included, where "size" refers to the diameter of the circular float, with units of mm. This subfolder contains multiple Excel files recording the float rotation angle as a function of time for different-sized circular floats over 10 cycles at a constant device operating speed. The numerical values in the Excel filenames represent the float size, with diameters ranging from 3 mm to 13 mm.
    • Additionally, in the main folder, a statistical data file named "Fig.3E-size-mean-std.csv" is included. This file records the mean and standard deviation (SD) of float rotation angles during device upward and downward motions over 10 cycles for different float sizes.
  • Figure 4: this folder contains data on how the shape of the float and the channel impacts the rotations. Fig. 4A: rotation tracking data for different floats; Fig. 4B: rotation tracking data for different channel shapes.
    • To verify the generality of the ratchet rotation phenomenon, cross-validation experiments were performed using floats of different shapes and devices with different cross-sectional shapes. In the "Fig.4A" folder, multiple Excel data files are stored. These data represent the float rotation angle as a function of time for different float shapes within a device with the same "windmill" cross-sectional shape. All experiments were conducted over 10 cycles; the filenames correspond to the respective float shapes.
    • In the "Fig.4B" folder, data are stored for experiments using devices with different cross-sectional shapes paired with a "windmill"-shaped float. These files contain the float rotation angle as a function of time. The filenames correspond to the respective device cross-sectional shapes.
  • Figure 5: this folder contains original SEM images on the braided fibers.
  • Figure 6: this folder contains data used in Figure 6, where a 3D printed device is used to hierarchically twist fibers. The STL file and the SEM images are included.

File: Supporting_Materials_Data.zip

Description: data used to generate figures in the supporting materials

• Supporting_Materials_Data
  • S1: rotation tracking data for different pause times. In the experiments, after the device moves upward to a designated position, it pauses for a period of time to allow the water surface to stabilize before moving downward; this complete process constitutes one cycle. The duration of this pause is referred to as "pause time." To investigate the effect of pause time on float rotation, this folder contains two data files with pause times of 0.01 s and 10 s, respectively. These files record the float rotation angle as a function of time when the device operates at the same speed but with different pause durations. Both the float and the device are of "windmill" shape.
  • S2: rotation tracking data for combinations of fast/slow raising/lowering of the device. In the experiments, the upward and downward motions of the device are independently controlled. This folder contains data for three combinations of operating speeds: (i) fast upward and fast downward motion, (ii) slow upward and fast downward motion, and (iii) slow upward and slow downward motion. These data record the float rotation angle as a function of time for each condition. Both the float and the device are of "windmill" shape.
  • S3: rotation tracking data for mirrored devices. The float was placed in a mirrored configuration within a device of "windmill" cross-sectional shape, and the float rotation angle as a function of time was collected and compared with the original (non-mirrored) placement. The Excel files in this folder contain the rotation angle data as a function of time.
  • S4: rotation tracking data over 10 cycles. This dataset decomposes the rotation data for different float shapes within a device of "windmill" cross-sectional shape over 10 cycles. For each float shape, the rotation angle change during each individual upward or downward motion of the device is isolated. Folder names indicate the float shape and the direction of device motion (upward/downward).
  • S5: rotation tracking data for different float shapes. When placed at the central interface within the device, the float stabilizes at several low-energy positions under capillary forces. This folder contains statistical data on the static orientation of different float shapes within a device of "windmill" cross-sectional shape. Filenames indicate the respective float shapes.
  • S7: rotation tracking data for circular floats made from different materials. This folder contains data on the static orientation of floats fabricated from different materials within a device of "windmill" cross-sectional shape. Filenames indicate the respective material names.
  • S9: rotation tracking data for circular floats with prescribed defects. In this experiment, a circular float with a deliberately introduced micro-defect was designed to observe changes in rotation behavior. The file "Defective float angle.csv" contains the rotation angle of the defective float as a function of time, which is compared with the rotation data of the original circular float. The file "Defective float.csv" contains the static angular orientation data of the defective float within a device of "windmill" cross-sectional shape.
  • S10: rotation tracking data for individual cycles with different channel shapes. Similar to S4, this folder contains data for devices with different cross-sectional shapes paired with a "windmill"-shaped float. The rotation angle data for each individual upward or downward motion of the device are isolated. Filenames indicate the device cross-sectional shape and the direction of device motion.
  • S11: rotation tracking data for different operation speeds. To investigate whether ratcheting behavior can occur when a circular float is placed within a device of circular cross-section, this folder collects float rotation angle data as a function of time at different device operating speeds. In the filenames, "speed" refers to the vertical operating speed of the device; the numerical value indicates the specific speed in mm/min.
  • S12: rotation tracking data for miniaturized devices. To verify whether ratcheting behavior persists upon system miniaturization, the original device was scaled down to 30% of its original size and paired with a 2 mm-diameter circular float. The float rotation angle data were collected and compared with those from the original-sized device paired with a 10 mm-diameter float. Excel files contain the rotation angle data, with conditions indicated in the filenames.
  • S14: rotation tracking data for devices with altered pitches. In this study, the device contains an internal helical structure; in the original device, the cross-section rotates 180° from top to bottom. To investigate the effect of helical pitch density on float rotation, experiments were conducted with the helical pitch reduced to 0.5× and 0.2× of the original value, and the results were compared with the original device. This folder contains the above data, with conditions indicated in the filenames. Additionally, experiments were performed with the pitch unchanged but the device height increased to 5× the original height. Both the device and float are of "windmill" shape.
  • S15: statistical data for repeated runs using two identical devices. To assess the reproducibility of the experimental phenomenon, two sets of "windmill"-shaped devices and floats were each subjected to 100 repeated cycles. The results for each individual upward or downward motion were isolated, and the float rotation angle for each single stroke was extracted for statistical analysis. The data in this folder represent the float rotation angle for each individual stroke.
  • S17: rotation tracking data for clockwise and counterclockwise channels/floats operated at different speeds. In this experiment, devices with "windmill" cross-sectional shapes possess four distinct chiral configurations. Mirroring the "windmill" cross-section yields an alternative shape; these two cross-sectional shapes are designated as S1 and S2, respectively. The internal helical structure of the device can also be oriented in either clockwise or counterclockwise direction from top to bottom. To investigate the effects of these structural parameters on float rotation, circular floats were paired with all four configurations for experiments. Within this folder, each subfolder is named "speed-###," where ### indicates the vertical operating speed of the device in mm/min. The Excel files within each subfolder contain the float rotation angle data; filenames indicate the cross-sectional shape (S1/S2) and the helical orientation (clockwise/counterclockwise).

Sharing/Access information

For additional information, please reach out to the the authors at czeng2024@sinano.ac.cn