The Unsung Hidden Heroes of Development: Materials Science
Everyday Innovations, Big Economic Impact. The role of materials science in improving life and prosperity within developing countries.
Fernand Legér’s Les Disques, 19181
Mzee Malilo had a problem.
In the morning, when Malilo’s daughter was sent out with the old, slightly rusty metal jerry can she used every day to collect water, the can finally gave up the ghost and water rushed out. It wasn’t the biggest problem Malilo had ever faced, but a problem it was, nevertheless.
Luckily, help was at hand. Just a short walk from Malilo’s house, small shops sold plastic 20-litre water containers — the kind everyone simply calls jerry cans. They were lighter, less prone to rust, easier to carry, and better suited to keeping water clean. So, a small purchase later, the family had a new HDPE plastic jerry can, and Malilo’s daughter set off to the river for the second time that day.
This is a deeply ordinary story across low- and middle-income countries. We can admit it’s not the most riveting opening scene. But this is not just a story about Malilo and a jerry can.
It is a story about the small innovations powering everyday improvements: the unsung heroes of development. Materials science is one of the most underrated forces in global development. So here is an ode to the materials that quietly make life a little easier, safer, cheaper, and less exhausting.
1. Aluminium-zinc sheets
The average family in Tanzania often lives under a sheet-metal roof, commonly corrugated iron: a low-cost way to create a versatile, long-lasting structure. But with tropical rainy seasons, heat, humidity, and corrosion, roofs can degrade quickly.
Enter aluminium-zinc.
Aluminium-zinc coated steel protects the metal beneath. Instead of a roof slowly rusting, leaking, and needing patching or replacement, the coating helps the roof last much longer under harsh weather conditions.
Estimated saved costs
A small rural roof might need around 35 square metres of roofing material once overlap and cutting waste are included. Using rough regional price assumptions, a galvanised iron roof might cost around US$200–240 installed, while an aluminium-zinc roof might cost around US$300–345 installed.
That makes the aluminium-zinc roof more expensive upfront. But if the cheaper galvanised roof needs to be replaced multiple times over 40 years, the more durable option could save roughly US$300–400 over the same period. That is before counting the less visible benefits: fewer leaks, fewer repairs, less time spent patching gaps, no health/safety issues, and better rainwater harvesting.
Life changing? No. Life enhancing? 100%.
2. Long-lasting insecticidal nets
Malaria still imposes a huge burden across sub-Saharan Africa. It is not only a health problem; it is also an economic one. A malaria episode can mean clinic costs, medicine costs, travel costs, lost workdays, missed school, and someone else in the household giving up time to care for the sick person.
Mosquito nets are one of the simplest safety measures. Older insecticide-treated nets needed regular retreatment to stay effective. Long-lasting insecticidal nets, or LLINs, improved the basic object itself: the insecticide is built into the fibres, so the net remains protective for much longer and through repeated washing.
That is the materials science part. The breakthrough is not a shiny machine or a new app. It is a better fibre, a better treatment, and a better household object.
Estimated saved costs
The cost of malaria can be surprisingly large for a household. Even a “normal” malaria episode can mean several lost workdays plus treatment costs. A person with malaria may lose around 3–4 workdays, and once treatment, transport, and care time are included, the cost to a household can easily become meaningful.
For a family in a high-transmission area, avoiding even one malaria episode per year can save roughly US$25–50 in lost income and direct costs. Against that, an LLIN costing only a few dollars and lasting around three years is an unusually good bargain.
The point is not that one mosquito net solves malaria. It does not. But it turns a cheap household item into a quiet productivity tool: fewer bites, fewer sick days, fewer clinic trips, and more nights where people simply sleep safely.
3. The rise and rise of accessible LED bulbs
Just a few years ago, many rural households in East Africa had limited access to reliable electricity. Today, small solar systems, better batteries, and improved lighting are increasingly available.
LED bulbs are a huge part of that story.
The technology itself has been around for years, but what matters is accessibility. Basic LED bulbs are now cheap, widely available, and much more efficient than old incandescent bulbs. For a household using a small solar-powered battery, this matters enormously. A 60W incandescent bulb drains a small system quickly. An LED bulb can provide many more hours of light from the same stored energy.
That difference can mean children finishing homework after dark, a shop staying open a little longer, or a household reducing spending on kerosene.
Estimated saved costs
For a rural family, a small solar home system with LED bulbs may cost more upfront than buying kerosene day by day. But the calculation changes once the system lasts long enough.
One LED replaces many incandescent bulbs over its lifespan. The U.S. Department of Energy states that residential LEDs use at least 75% less energy and can last up to 25 times longer than incandescent lighting. On a small $50–80 solar home system, that efficiency matters: a comparable LED can give many more hours of light from the same battery charge than an incandescent bulb. Versus kerosene at roughly $0.80 per litre and around 1 litre per week, a solar-LED system could pay for itself within about two years and save around $35–40 per year after that.
It also gives far more light per unit of electricity. Compared with kerosene lighting, a solar-LED setup can pay for itself within months or a couple of years, depending on the system cost and household usage. After that, the household keeps the light and reduces repeat spending.
Again, not a dramatic revolution. Just better light, for longer, at lower running cost.
4. HDPE water containers
And of course we have all things water containers: jerry cans, household tanks, and industrial tanks alike.
Metal containers deteriorate quickly in tropical environments. Beyond just leaking, rusting, and becoming a general nuisance, they can also affect water quality over time. HDPE has become the quiet hero here: high-density polyethylene is durable, light, weather-resistant, and much better suited to regular household water storage.
A small HDPE jerry can will not transform someone’s life on its own. But it is still a better object: lighter to carry, less likely to rust, easier to clean, and less likely to fail at the worst possible moment.
The bigger impact comes from HDPE household tanks. A larger tank, costing roughly $50–120 depending on size and quality, can reduce the number of water collection trips a household needs to make. For women and girls in East Africa, who often carry the burden of household water collection, that can mean a real reduction in back-breaking labour.
Estimated saved costs
A $100 household tank that reduces water collection trips from daily to roughly twice weekly could free around 390 hours per year.
The calculation is simple: assume a 6 km water collection trip and an average walking speed of 4 km/hour. That gives 1.5 hours per trip. If improved storage reduces around 260 trips per year, that is:
260 trips × 1.5 hours = 390 hours saved per year.
At an implied time value of $0.50/hour, that is about $195/year in opportunity cost returned — nearly two months of income — from a one-time $100 purchase.
Container replacement saving comes on top. A durable HDPE jerry can or tank also avoids some of the repeated replacement cost of rust-prone metal containers. That saving may only be $25–35 over 15 years, but combined with the time saving, the humble plastic water container starts looking less humble.
Slightly better stuff
Mzee Malilo’s daughter probably will not think twice about the new jerry can. It will fade into the background of her day, joining the aluminium-zinc roof above her head, the mosquito net she sleeps under, and the LED bulb that lets her finish her homework after dark.
So many of the best innovations are the ones that disappear into daily life, quietly solving problems people should not have had to think about in the first place.
Everyone loves a headline-worthy breakthrough: mRNA vaccines, mobile money, AI-for-good pilots. All worthwhile.
But development is not only built on grand visions and big bets. A great deal of it is built, quite literally, on just slightly better stuff.
Appendix: Assumptions, Calculations, and Sources
This appendix explains the rough assumptions behind the cost examples in the article. The figures are intended as illustrative estimates rather than universal prices. Actual savings vary by household size, local prices, product quality, distance to services, and how long the product lasts in real use.
1. Aluminium-zinc roofing compared with galvanised iron roofing
Cost assumption
The roof is assumed to require approximately 35 m² of sheet material, including allowance for overlap and cutting waste.
Estimated material prices used in the article:
Galvanised iron roofing sheet: KSh 500 per m², or approximately KSh 17,500 for 35 m².
Aluminium-zinc coated roofing sheet: KSh 875 per m², or approximately KSh 30,600 for 35 m².
Additional nails, ridge pieces, and basic labour: KSh 10,000–15,000.
Using an approximate exchange rate of KSh 130–135 per US dollar, this gives the following installed cost estimate:
Galvanised iron roof: approximately US$200–240 installed.
Aluminium-zinc roof: approximately US$300–345 installed.
Long-term cost comparison
Over a 40-year period, if galvanised iron roofing needs to be replaced three times, the total installed cost would be approximately:
Galvanised iron: US$600–720 over 40 years.
Aluminium-zinc: US$300–345 over 40 years.
This implies an estimated lifetime saving of around US$300–400 from choosing aluminium-zinc roofing, assuming the higher-durability roof lasts through the full period. At a rural income proxy of about US$4 per day, this is roughly equivalent to 2–3 months of income.
Sources
Safal Steel. “The Benefits of Aluminium-Zinc Coated Steel.” 21 February 2022.
https://www.safalsteel.com/2022/02/the-benefits-of-aluminium-zinc-coated-steel/Safal Steel. “Zincal®: Steel Coated with Aluminium and Zinc.”
https://www.safalsteel.com/zincal/Mabati Rolling Mills. “ZINCAL® Metal Coated Steel Roofing Design.”
https://mabati.com/coated_steel_product/zincal/ZWCC. “Roofing Iron Sheets and Prices in Kenya.”
https://www.zwccrusher.com/index.php/2025/08/24/roofing-iron-sheets-and-prices-in-kenya/
Note: This source should be treated as a market-price reference only. The URL appears to be dated 2025, so it should not be described as “2024 pricing” unless separately verified.ScienceDirect 2024 study, Mbeya, Tanzania.
Note: full citation details should be added before publication if this source is kept.
2. Long-lasting insecticidal nets
Effectiveness assumption
The article assumes that long-lasting insecticidal nets reduce the need for regular insecticide retreatment compared with older insecticide-treated nets.
WHO’s durability monitoring guidance describes long-lasting insecticidal nets as products whose field durability should be monitored under operational conditions and whose useful life is commonly planned around multi-year replacement cycles. For the article body, the safer wording is that LLINs are designed to remain effective for repeated washing and around three years of recommended field use.
Financial-cost assumption
The article treats malaria as both a health burden and a household economic burden. Costs may include:
lost workdays;
treatment costs;
transport to clinics;
school absenteeism;
care time from other household members.
The article uses a simple household-level example: if one malaria episode causes around 3–4 lost workdays, plus treatment and travel costs, then avoiding even one episode can plausibly save a household around US$25–50. This is not a universal figure; it varies by country, household income, distance to care, severity of illness, and whether treatment is subsidised.
The wider economic point is that malaria creates large costs beyond the clinic bill. The source list below supports the general claim that malaria has major household and public-health costs.
Sources
World Health Organization. “World Malaria Report 2023.” 2023.
https://www.who.int/teams/global-malaria-programme/reports/world-malaria-report-2023World Health Organization. “Guidelines for Monitoring the Durability of Long-Lasting Insecticidal Mosquito Nets Under Operational Conditions.” 2011.
https://www.who.int/publications/i/item/9789241501705GiveWell. “Mass Distribution of Insecticide-Treated Nets.”
https://www.givewell.org/international/technical/programs/insecticide-treated-netsAkazili, J., Aikins, M., & Binka, F. N. “Malaria Treatment in Northern Ghana: What Is the Treatment Cost per Case to Households?” African Journal of Health Sciences, 14(1), 70–79.
DOI: 10.4314/ajhs.v14i1.30849Deressa, W., Hailemariam, D., & Ali, A. “Economic Costs of Epidemic Malaria to Households in Rural Ethiopia.” Tropical Medicine & International Health, 12(10), 1148–1156. 2007.
https://pubmed.ncbi.nlm.nih.gov/17956496/Mori, A. T., Mallange, G., Kühl, M.-J., & Okell, L. “Cost of Treating Severe Malaria in Children in Africa: A Systematic Literature Review.” Malaria Journal, 23, Article 334. 2024.
DOI: 10.1186/s12936-024-05173-wYukich, J., et al. “Sustaining LLIN Coverage with Continuous Distribution.” Malaria Journal. 2020.
https://pmc.ncbi.nlm.nih.gov/articles/PMC7164342/
3. LED lighting and off-grid solar products
Technology assumption
The article assumes that LED bulbs use substantially less electricity than incandescent bulbs and last much longer. This matters especially for small solar home systems, where battery capacity is limited.
The U.S. Department of Energy states that residential LEDs, especially ENERGY STAR-rated products, use at least 75% less energy and last up to 25 times longer than incandescent lighting.
Estimated saving
The article uses the following illustrative assumptions:
Small solar home system with two LED bulbs: US$50–80 upfront.
Kerosene alternative: approximately US$0.80 per litre.
Household kerosene use: roughly 1 litre per week.
Annual kerosene spending avoided:
US$0.80 × 1 litre/week × 52 weeks = US$41.60/year.
Estimated payback period:
US$50 system ÷ US$41.60/year = 1.2 years, or about 14–15 months.
US$80 system ÷ US$41.60/year = 1.9 years, or about 23 months.
So, under these assumptions, a solar-LED system could pay for itself within about 15–24 months and save around US$35–40/year after that, depending on the actual upfront cost, household lighting use, and kerosene price.
The “one LED replaces many incandescent bulbs” claim is based on LED lifespan and efficiency compared with incandescent lighting. The article should avoid over-precise wording unless the exact bulb specifications are known.
Sources
U.S. Department of Energy. “LED Lighting.” Energy Saver.
https://www.energy.gov/energysaver/led-lightingGOGLA. “Market Insights & Data.”
https://gogla.org/market-insights-data/GOGLA and World Bank ESMAP. “Off-Grid Solar Market Trends Report 2024.”
https://old.gogla.org/reports/off-grid-solar-market-trends-report-2024/FairPlanet. “The Counterfeit Components Delaying Africa’s Energy Transition.”
https://www.fairplanet.org/story/the-counterfeit-components-delaying-africas-energy-transition/Engineering for Change. “d.light D180.”
https://www.engineeringforchange.org/solutions/product/d-light-d180/
4. HDPE water containers and household tanks
Important distinction
The article discusses two related but different products:
20-litre HDPE jerry cans — small, portable water containers.
Larger HDPE household tanks — fixed or semi-fixed storage tanks that can reduce the number of water collection trips a household needs to make.
The article should not attach the full time-saving calculation to a single 20-litre jerry can. A jerry can is useful because it is lighter, cleaner, easier to carry, and less prone to rust than a metal container. The larger household time-saving effect comes from improved water storage, especially through larger tanks.
Household tank time-saving assumption
The article assumes a household water collection trip of 6 km and an average walking speed of 4 km/hour. This gives:
6 km per trip ÷ 4 km/hour = 1.5 hours per trip.
If improved household storage reduces approximately 260 trips per year, this frees:
260 trips × 1.5 hours = 390 hours per year.
At an implied rural time value of US$0.50 per hour, equivalent to about US$4 per day, this time saving is valued at:
390 hours × US$0.50 = US$195 per year.
This calculation is intended as an illustrative opportunity-cost estimate, not a universal household saving. The actual saving depends on distance to water, household size, tank size, water reliability, seasonality, and local prices.
Container replacement assumption
Estimated container costs:
HDPE jerry can: US$5–8, lasting approximately 10+ years.
Metal can: US$8–12, rusting out after approximately 3–5 years.
Over a 15-year period:
Metal cans: approximately 3–4 cans, or US$30–45.
HDPE can: approximately 1 can, or around US$6.
This implies a rough replacement saving of around US$25–35 over 15 years. This is a secondary saving. The larger economic effect in the article comes from time saved through improved household water storage.
Because reliable current Tanzania-specific online pricing for a 20-litre HDPE jerry can was not confirmed, the jerry-can prices above should be treated as rough market assumptions, not verified Tanzania prices.
Sources
Local/regional market-price checks for HDPE containers and household tanks.
Household water collection time calculation based on the article’s stated assumptions: 6 km per trip, 4 km/hour walking speed, and 260 avoided trips per year.
Replacement comparison based on the practical durability difference between rust-prone metal containers and HDPE plastic containers.
Léger, Fernand. Les Disques [The Disks]. 1918–1919, oil on canvas, 51 1/8 × 38 1/4 in. Los Angeles County Museum of Art, Los Angeles. LACMA Collections. Accessed 3 July 2026.
LACMA lists the work as The Disks, dated 1918–1919, oil on canvas, in its collection.