Gecko Adhesion Challenge

Overview

Students explore how gecko feet stick to surfaces, then engineer and test glue-free adhesive prototypes. They work collaboratively to meet a weight-holding challenge on a vertical surface and reflect on what makes adhesion successful.

Learning intentions

• WALT describe how gecko toe structures help adhesion work without glue.
• WALT investigate van der Waals forces as a scientific idea linked to adhesion.
• WALT design, build, and test a reusable adhesive device that can hold a stated mass on a vertical surface.
• WALT evaluate results and improve prototypes using evidence.

Success criteria

• I can explain, in my own words, how surface contact and tiny structures help materials stick.
• I can test different adhesive designs fairly and record results accurately.
• I can improve my design after testing, showing clear evidence of better adhesion.
• I can build a reusable device that holds 100 g on a vertical surface.

Curriculum links

• Technology: designing and developing digital and physical solutions through experimentation, modelling, and iteration.
• Science capability: using observations and basic scientific ideas to explain phenomena.
• NCEA-linked skills: practical testing, measurement, and evaluation for improvement (adapted to Year 5–6 level).
• Key competencies in action: managing self, relating to others, and thinking critically through evidence-based refinement.

Lesson structure (45 minutes)

1. 5 mins — Starter: Gecko mystery reveal Show a short, simple demonstration: a “sticky” replica or image of toe pads. Students predict what makes geckos stick and share one idea for how engineering could copy nature.

2. 10 mins — Investigate toe mechanics (hands-on stations) In small groups, students examine gecko-foot replicas or textured materials (e.g., bristle-like fibres, felt pads, foam grips). They discuss: What parts touch? How could more contact create more sticking?

3. 8 mins — Mini science: van der Waals (teacher-guided) Use a kid-friendly explanation: when a material makes very close contact with a surface, tiny attractive forces can help it stay attached. Students connect this to “more tiny contact points” rather than glue.

4. 12 mins — Engineering challenge design + first build Groups choose one material/structure idea and quickly build a prototype adhesive device (no traditional glue). They label parts and plan how they will test “fairly” (same surface, same placement, same time).

5. 6 mins — Test and measure (100 g goal) Each group tests on a vertical surface. Add mass gradually (with a simple hanger or clip) until it fails, then record the highest mass held. Students observe and note what changed at the failure point (peeling, falling, surface damage).

6. 4 mins — Improve fast: second attempt or adjustment Students make one improvement based on evidence (e.g., change fibre length, increase spacing, reshape pad, adjust pressing technique). They perform a quick second test if time allows, or set a clear next step for Lesson 4.

Resources

• Gecko toe replica cards/images or a few physical replicas/texture samples
• Testing surfaces: tiles, plastic sheet, painted board, and one “rough” and one “smooth” option
• Materials for prototypes: felt, fabric strips, foam pads, soft rubber sheets, bristle/broom fibres, small pipe cleaners, sticky-backed paper alternatives (only if agreed as non-glue contact)
• Mass set or cup-and-hanger with weights totalling at least 100 g
• Clip/hanger tool for attaching the weight to the adhesive prototype
• Clipboards, student recording sheets (mass held, observations, next improvement)
• Safety items: eye protection (optional but sensible) and cleaning wipes
• Timer for consistent testing
• Teacher checklist for success criteria

Assessment

• Teacher observation checklist: students justify design choices using evidence from tests and toe mechanics observations.
• Prototype testing evidence: recorded mass held, notes about failure, and at least one improvement plan.
• Student reflection prompt (quick oral or written): “What helped adhesion most, and why do you think that happened?”

Differentiation

• Support: provide a limited materials choice; use sentence starters (“I think it stuck because…”, “Next time we will…”); assign roles (builder, tester, recorder) to reduce decision overload.
• Targeted scaffolding: give a simple testing rubric (same surface, same time, same pressure/placement as best as possible).
• Extension: require two-factor testing—change only one variable at a time (material type vs texture vs contact pressure) and produce a short “evidence claim” statement.
• EAL/SEN: allow drawing and labelled diagrams in place of full writing; pre-teach key words with visuals (adhesion, surface, test, evidence, improve).

Extension (optional)

• Advanced learners design and prototype a gecko-inspired application: either a medical bandage concept (doesn’t need glue, removable, gentle adhesion) or a space technology concept (sticks in microgravity by maximising contact). They present: target user/environment, material choice, testing idea, and how they would evaluate success (e.g., hold time, removability, reusability).