# Superhydrophobic surfaces: the lotus effect, read on a protractor

> A contact-angle protractor from 0° to 180°: water spreads below 90°, beads above it, and beyond 150° (with drops sliding off below 5°) the surface is superhydrophobic, like the lotus leaf at 163°. Underneath, the two ways a drop sits on roughness (Wenzel, filling the grooves; Cassie–Baxter, resting on air), drops rolling off with the dirt, and the lotus leaf’s papillae and wax tubules in numbers.

- Page: https://www.labcanvas.com/templates/graphical-abstracts/superhydrophobic-surfaces-lotus-effect-read-protractor
- Open in the LabCanvas editor (LabCanvas account): https://www.labcanvas.com/editor.html?template=superhydrophobic-surfaces-lotus-effect
- Updated: 2026-10-14
- Category: Graphical abstracts
- Method: Graphical abstract
- Starting materials: A surface with micro- and nano-scale roughness and low surface energy
- Product: A superhydrophobic, self-cleaning surface: contact angle above 150°, drops roll off
- Key result: Above 150° and sliding below 5° (Zhang et al. 2021); lotus leaf 163°, 3431 papillae per mm², wax tubules 80–120 nm thick, adhesion 8–18 µN (Ensikat et al. 2011)
- Figure: 1920 × 1080 px, 128 editable layers (1 generated objects with settings)

## Steps

1. **The scale**: Hydrophilic below 90°, hydrophobic above 90°, superhydrophobic above 150° with a sliding angle below 5° (Zhang et al. 2021)
2. **Wenzel or Cassie–Baxter**: In the Wenzel state water fills the grooves; in the Cassie–Baxter state the drop rests over air, touches less, beads more and rolls off; roughness and low surface energy are both needed (Zhang et al. 2021; Ensikat et al. 2011)
3. **The lotus leaf**: 3431 papillae per mm² coated with wax tubules 80–120 nm thick; 163° contact angle and 8–18 µN drop adhesion (Ensikat et al. 2011)
4. **Self-cleaning**: Drops roll off and carry dust and contaminants away (Xue et al. 2024)

## Uses

- Graphical abstracts on superhydrophobic and self-cleaning surfaces
- Talks on wetting, the lotus effect and bioinspired coatings
- Teaching contact angles and the Wenzel and Cassie–Baxter states

## References

1. Ensikat, Ditsche-Kuru, Neinhuis & Barthlott, “Superhydrophobicity in perfection: the outstanding properties of the lotus leaf”, Beilstein J. Nanotechnol. 2011. https://doi.org/10.3762/bjnano.2.19 (primary)
2. Zhang et al., “A Review of Recent Advances in Superhydrophobic Surfaces and Their Applications in Drag Reduction and Heat Transfer”, Nanomaterials 2021. https://doi.org/10.3390/nano12010044 (review)
3. Xue et al., “A comprehensive review on self-cleaning glass surfaces: durability, mechanisms, and functional applications”, RSC Adv. 2024. https://doi.org/10.1039/d4ra06680d (review)
4. Wang, Wu & Nestler, “Wetting Effect on Patterned Substrates”, Adv. Mater. 2023. https://doi.org/10.1002/adma.202210745 (review)

Credit: Drawn by LabCanvas after Ensikat et al., Beilstein J. Nanotechnol. 2011 (doi:10.3762/bjnano.2.19); Zhang et al., Nanomaterials 2021 (doi:10.3390/nano12010044); Xue et al., RSC Adv. 2024 (doi:10.1039/d4ra06680d) and Wang, Wu & Nestler, Adv. Mater. 2023 (doi:10.1002/adma.202210745).

## Questions

**What does the “Superhydrophobic surfaces: the lotus effect, read on a protractor” template show?** A contact-angle protractor from 0° to 180°: water spreads below 90°, beads above it, and beyond 150° (with drops sliding off below 5°) the surface is superhydrophobic, like the lotus leaf at 163°. Underneath, the two ways a drop sits on roughness (Wenzel, filling the grooves; Cassie–Baxter, resting on air), drops rolling off with the dirt, and the lotus leaf’s papillae and wax tubules in numbers.

**What are the steps shown in “Superhydrophobic surfaces: the lotus effect, read on a protractor”?** 1. The scale: Hydrophilic below 90°, hydrophobic above 90°, superhydrophobic above 150° with a sliding angle below 5° (Zhang et al. 2021). 2. Wenzel or Cassie–Baxter: In the Wenzel state water fills the grooves; in the Cassie–Baxter state the drop rests over air, touches less, beads more and rolls off; roughness and low surface energy are both needed (Zhang et al. 2021; Ensikat et al. 2011). 3. The lotus leaf: 3431 papillae per mm² coated with wax tubules 80–120 nm thick; 163° contact angle and 8–18 µN drop adhesion (Ensikat et al. 2011). 4. Self-cleaning: Drops roll off and carry dust and contaminants away (Xue et al. 2024).

**What are the starting materials and the product?** Starting materials: A surface with micro- and nano-scale roughness and low surface energy. Product: A superhydrophobic, self-cleaning surface: contact angle above 150°, drops roll off.

**Which papers is “Superhydrophobic surfaces: the lotus effect, read on a protractor” based on?** Ensikat, Ditsche-Kuru, Neinhuis & Barthlott, “Superhydrophobicity in perfection: the outstanding properties of the lotus leaf”, Beilstein J. Nanotechnol. 2011 (doi:10.3762/bjnano.2.19); Zhang et al., “A Review of Recent Advances in Superhydrophobic Surfaces and Their Applications in Drag Reduction and Heat Transfer”, Nanomaterials 2021 (doi:10.3390/nano12010044); Xue et al., “A comprehensive review on self-cleaning glass surfaces: durability, mechanisms, and functional applications”, RSC Adv. 2024 (doi:10.1039/d4ra06680d); Wang, Wu & Nestler, “Wetting Effect on Patterned Substrates”, Adv. Mater. 2023 (doi:10.1002/adma.202210745).

**Can I edit the “Superhydrophobic surfaces: the lotus effect, read on a protractor” template?** Yes. Open it in the LabCanvas editor: all 128 layers are editable, including 1 generated objects (structures, plots, equipment) with their own settings. Change the text, colours and layout, then export PNG, TIFF, SVG or PDF.

**Do I need an account to use this template?** Not to view it here. To open and edit it, sign in to LabCanvas or create a free account (the free plan keeps up to 3 designs). Downloading the figure is part of LabCanvas Pro (US$19 a month or US$199 a year).