Iron Repair, With Micro-Care: A Novel Dissolvable Bio-inspired Microneedle Patch for Iron Delivery

References for Video:

All images of our original product and needle design were created by Averil and Wailea Lu or AI generated.

We retrieved our photos from the following websites:

OpenAI. (2026). ChatGPT. ChatGPT; OpenAI. https://chatgpt.com/

Cache, A. (2025, September 11). Iron infusions vs oral iron supplements: What's the difference. Clarendon Medical. https://clarendonmedical.com.au/blog/iron-infusions-vs-oral-supplements-difference/

News, A. S. (2021, May 11). Microneedle patch delivers antibiotics locally in the skin. Advanced Science News. https://www.advancedsciencenews.com/microneedle-patch-delivers-antibiotics-locally-in-the-skin/

Rose, A. (2026). Iron rich foods: Foods high in iron for health. Dailyiron.net. http://www.dailyiron.net/wp-content/uploads/2010/10/Iron-Deficiency-Prevalence-Women.png

Shipman, M. (2019, June 10). New microneedle technique speeds plant disease detection. NC State News. https://news.ncsu.edu/2019/06/microneedle-plant-disease-detection/

Triple Ring Technologies. (2024, December 18). Microneedle patch applicator. https://www.tripleringtech.com/case-studies/microneedle-patch-applicator/

The Problem: Iron deficiency affects over 2 billion people, but current treatments have limitations. When left unaddressed, it can progress to iron deficiency anemia, where hemoglobin levels are reduced.

Iron pills are relatively affordable but often cause gastrointestinal side effects, poor adherence and slow absorption levels into the body. Infusions are faster, but expensive, invasive, and require trained personnel. In low and middle-income countries, where iron deficiency is highly prevalent, limited access and high costs restrict treatments; highlighting the need for alternatives.

Solution: Re-engineering a novel dissolvable micro-needle patch using biomimicry.

Microneedles

Microneedles are transdermal drug delivery systems that use microscopic needles to deliver drugs, specifically drugs that require small doses. However, past research acknowledges that microneedles face design challenges like weak strength, diffusion and adhesion. Iron presents a unique challenge because it requires larger doses with low absorption, making current transdermal drug delivery systems ineffective. Hence, making iron delivery a good candidate for our biomimetic redesign of the conventional microneedle that aims to improve these challenges.

Biomimicry

Studies suggest porcupine quill-inspired needles increase adhesive grip while mosquito-inspired biopsy needles decrease tissue damage, both target microneedle design challenges we aim to solve.

Research Questions

Phase 1: Do biomimicry-inspired needle designs outperform conventional needle designs in insertion, penetration, and diffusion?

Phase 2: Based on phase 1, can we develop an improved microneedle design that performs better than the conventional needle upon retesting?

Phase 3: How can the final product’s potential success be evaluated in terms of cost, production, and design?

Phase 1 - Macro Scale Design & Testing

Research was conducted and three microneedle designs were modeled in Shapr3D and 3D printed using polylactic acid (PLA). The conventional needle served as the control.

Each 1 cm × 1 cm patch contained four identical needle types arranged in a 2 × 2 grid: (Mosquito-Needle, Porcupine Needle, Conventional Needle)

Test medium was developed to simulate skin using agar-based gelatin in petri dishes / trays. For the insertion experiment, three skin barriers were created (hard, soft, regular).

Each patch consisting of each microneedle design type was inserted into each of the three skin models three times to help ensure consistency for insertion experiment; the other experiments used regular agar skin only.

Tested each microneedle design patch with the following experiments (Image 7):

Insertion and Adhesion Ratio

Each needle was inserted into each agar type while attached to a spring scale to measure peak insertion and removal forces. Adhesion ratio was calculated by:

(Peak force in/out) * 100

Penetration Success Rate and Depth

Needles coated in food-dye were inserted into regular agar under a 5 g load. Depth (mm) were measured by slicing the agar. Penetration success rate was measured by:

(Original needle count - needles penetrated) * 100

Diffusion

Food-dye coated needles were inserted into regular agar. Diffusion was recorded every minute for 10 minutes using image analysis software and quantified 2D diffusion percentage over time.

Phase 2 – Analyze & Design of New Prototype Model

An optimized needle design was developed; incorporating strengths and eliminating weaknesses from Phase 1 findings.

Two 5cm x 5cm patches each with 96 needles were 3D printed.

Steps 2-4 from Phase 1 were repeated for the MIron (novel needle) and Conventional needle patch.

Phase 3 - Analyze Commercial Feasibility

Conduct a literature-based cost analysis by reviewing scientific studies, economic models, and microneedle market projections to evaluate scalability.

Statistical Analysis

A standardized scoring system was used to quantify penetration depth (mm) and tissue damage index (colour area %). To determine statistical significance, phase 1 data were analyzed using a two-way ANOVA to compare multiple groups (microneedles) and factors (skin types), while Phase 2 used unpaired two-tailed t-tests to assess differences between two independent groups.

Phase 1

Conventional microneedle’s smooth, sharp geometry enabled easy insertion but resulted in poor adhesion. It achieved an 8 mm penetration depth with the lowest tissue damage (score = 2), indicating minimal agar tissue disruption. However, it performed significantly worse in adhesion ratio (hard agar: 82% ± 0.01%, p>0.05), penetration success rate (42% ± 8.33%), and diffusion rate at 10 min (16.33% ± 7.38%; n = 3, p < 0.05), reflecting its lack of surface features.

Mosquito-inspired microneedle’s serrated edges improved adhesion and diffusion but increased tissue damage and limited penetration. It achieved the highest adhesion ratio (100% ± 0.02%, p>0.05), penetration success rate (92% ± 8.33%), and diffusion rate (46.09% ± 2.57%; n = 3, p < 0.05). However, it had the lowest penetration depth (3 mm) and highest tissue damage (score = 5) due to tearing from its bulky, jagged geometry.

Porcupine-inspired microneedle’s downward-facing barbs enhanced penetration but caused instability. It demonstrated strong adhesion (90% ± 0.03%, p>0.05) and penetration success (83% ± 8.33%; n = 3, p < 0.05). Its downward barbs guided dye flow and achieved the greatest penetration depth (9.3 mm). However, it showed tissue damage (score = 4) and uneven force distribution.

Phase 2

Building on these findings, we designed the final MIron design to integrate key features from each prototype. It retained a sharp conical base (conventional-inspired) for low-force insertion, incorporated a helical groove (porcupine-inspired) to guide downward flow and improve penetration, and added subtle surface textures (mosquito-inspired) to enhance adhesion without increasing damage.

MIron demonstrated significantly improved performance over the conventional design due to its novel helical structure. Penetration success increased to 97% ± 0.01% compared to 51% ± 0.01% for the conventional needle, increasing by 47% (n = 3, p<0.01). MIron's penetration depth of 8 mm indicated a successful response to the mimicked downward-flow mechanism. Adhesion ratios were consistently higher across all agar types: 107% ± 0.38% vs 102% ± 1.16% (hard), 106% ± 1.23% vs 95% ± 1.15% (regular), and 108% ± 1.03% vs 90% ± 2.47% (soft) (n = 3, p<0.05). Tissue damage maintained comparable to the conventional, indicating improved performance from phase 1 prototypes.

Phase 3

MIron is proposed as a weekly patch using PLGA-PEG polymers infused with iron nanoparticles and protective packaging, aligning with reported manufacturing costs of $0.50–$5.00 per unit. As the microneedle market grows, projected to reach $4.46 billion by 2030, advances in scale and manufacturing efficiency are expected to further reduce costs. Economic analyses define cost-effectiveness below $30 per treatment, while studies report >87% estimated savings, supporting that MIron is economically viable and increasingly affordable at scale.

Prior Research

These findings are supported by studies, reinforcing our design choices integrated into our project. Key features identified in prior studies, such as mosquito-inspired serrations and porcupine quill-inspired geometry for enhanced adhesion, were considered in our design process. Literature on spiral microgrooves enhancing directional drug loading and reducing friction, support our novel helical design. Prior studies show microneedles deliver iron nanoparticles with >80% sustained release over 12 days, we aimed to advance this approach as a commercially viable product.

Hypothesis

The results of this study support our hypothesis: bio-inspired microneedles improve specific performance metrics over conventional needles, but still need improvements. Mosquito outperformed in adhesion and diffusion, but increased damage. Porcupine improved penetration but had uneven force distribution. Conventional inserted easily but lacked adhesion and diffusion. However, our MIron needle consistently improved insertion, penetration, and diffusion rates compared to the conventional and our phase one designs.

Limitations

Agar doesn’t fully mimic human skin.

PLA prototypes doesn't mimic dissolvable polymer structures.

Dye diffusion doesn't mimic iron nanoparticle delivery.

Manual insertion may not be accurate.

Prototype sizes were not to scale of real microneedles.

The MIron patch was not tested for dissolvability.

Conclusion

These findings suggest that biomimetic designs can improve microneedle challenges to improve its overall performance for drug delivery. Our results support further development of MIron, a weekly dissolvable biomimetic patch that could improve comfort, adherence and accessibility for iron delivery. This work provides a foundation for future studies exploring real iron loading, biological absorption, and clinical feasibility.

Immediate Future Directions and Improvements:

Using our microneedle designs to test with real iron nanoparticles to evaluate more accurate controlled release.

Use of polymer-based prototype models to measure stronger dissolvability within our biomimicry design.

Use of automated testing and insertion systems to gather stronger insertion data.

Use of animals to test, simulate and mimic human skin to gain better insights on how our microneedle patch could work inside live specimens.

Further research to confidently and safely bring our product to market.

Engagement of microneedle and needle manufacturers to further assess cost and production feasibility.

Thank you for taking the time to learn about our project! We are extremely grateful for our science teacher, Ms. I, who has given us valuable feedback and support. To our parents, we are very appreciative of your endless support. Thank you to PrintInQuality, a business ran by our fellow classmates, that helped us 3D print our microneedle designs. We want to extend our thanks to the volunteers, judges, and delegates of GVRSF for their time and help. Finally, a big thanks to the many women and young girls that told us their personal stories, struggles, and opinions about iron deficiency that inspired our project.

References:

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Dixon, A. R., & Vondra, I. (2022). Biting Innovations of Mosquito-Based Biomaterials and Medical Devices. Materials, 15(13), 4587.https://doi.org/10.3390/ma15134587

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Images

All photos were retrieved from the following websites:

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