Recycled Materials in Engineering Design

A restaurant threw out 3 grams of shell. Engineers turned it into a robot that lifts 680 grams. Think about that. Millions of tons of crustacean shells end up in landfills every year. Leftover langoustine tails stripped for meat, headed for the bin. One lab at EPFL in Switzerland asked a different question. What robotics usually needs:  ↳ Expensive engineered composites  ↳ Complex manufacturing  ↳ Materials that end up as e-waste  ↳ Designs that fight against flexibility What Josie Hughes' CREATE Lab built instead:  ↳ Robotic actuators from discarded langoustine exoskeletons  ↳ 3 grams of shell lifting over 200× its own weight  ↳ 8 bending cycles per second—fast enough for real gripping  ↳ Swimming robots reaching 10–11 cm/s in water  ↳ Grippers strong enough to pick up a tomato or a pen The reason it works? Nature already solved the engineering. Crustacean shells merge hard plates with flexible joints. That combination of stiffness and flexibility is nearly impossible to replicate with synthetic materials. The segmented geometry allows rapid, high-torque motion—exactly what you need for grasping and swimming. Here's the part that stopped me: When the device is done, the biological shell biodegrades. The motors and elastomers get reused. Circular design, built into the system from day one. Lead author Sareum Kim calls it the first proof of concept that directly integrates food waste into a working robot while embracing reuse and recycling. They call the field "necrobotics"—dead biological structures engineered into functional machines. No temperature control. No nutrients. No sterile environments. Just kitchen waste becoming high-performance hardware. The ripple effect:  1 lab proves shells can power robots  10 teams replicating means it's real  100 applications means agriculture, monitoring, low-cost automation all get cheaper, greener options  At scale = robotics stops creating waste and starts using it Picture a farmer in a remote region. A low-cost gripper—built from shells that would've rotted—sorting produce. No expensive imports. No e-waste when it breaks down. Just a tool that came from the earth and returns to it. We spent decades engineering materials from scratch. This team asked a simpler question: what if the best actuator was already sitting in the trash? Follow me, Dr. Martha Boeckenfeld, for stories where waste becomes wonder. ♻️ Share if you think the best engineering sometimes starts in the trash.

Back in 2019, Google set a bold goal to use recycled materials in all our new consumer hardware. Now we’ve hit several exciting milestones, including the Pixel 10a, which is made with at least 36% recycled materials based on product weight. Choosing recycled content helps reduce the environmental impact of extraction, supports more sustainable supply chains, and enables designing products differently from the start. But in the journey to a circular economy, it’s best to travel together. That’s why we distilled our insights into our first Recycled Materials Guide—an open-source resource detailing how we’ve integrated recycled plastics, metals, and critical minerals into our hardware products. By sharing our technical “how-to,” I know we can help the entire industry move toward a more sustainable model. Check out the full guide here and share it with friends and colleagues who work in this space. ⤵️ goo.gle/4ds9H6F

𝐓𝐲𝐫𝐞 𝐑𝐞𝐜𝐲𝐜𝐥𝐢𝐧𝐠 – 𝐀 𝐬𝐮𝐬𝐭𝐚𝐢𝐧𝐚𝐛𝐥𝐞 𝐚𝐧𝐝 𝐡𝐢𝐠𝐡-𝐯𝐚𝐥𝐮𝐞 𝐬𝐨𝐥𝐮𝐭𝐢𝐨𝐧 𝐭𝐨 𝐭𝐫𝐚𝐧𝐬𝐟𝐨𝐫𝐦 𝐰𝐚𝐬𝐭𝐞 𝐢𝐧𝐭𝐨 𝐞𝐧𝐠𝐢𝐧𝐞𝐞𝐫𝐢𝐧𝐠 𝐫𝐞𝐬𝐨𝐮𝐫𝐜𝐞𝐬 !! Waste tyre recycling is a proven environmental engineering practice that converts end-of-life tyres into reusable materials for road construction, landscaping, and infrastructure applications—reducing landfill burden and conserving natural resources. The process involves mechanical and thermal treatments to extract rubber, steel, and textile fibers, enabling their reintegration into sustainable construction systems such as asphalt pavements, shock-absorbing layers, and erosion control solutions. 📌 𝐄𝐧𝐯𝐢𝐫𝐨𝐧𝐦𝐞𝐧𝐭𝐚𝐥 𝐑𝐞𝐚𝐥𝐢𝐭𝐲: ✓. Millions of tyres discarded annually, creating long-term landfill. ✓. Non-biodegradable nature leads to persistent environmental pollution. ✓. Open dumping promotes mosquito breeding and public health risks. ✓. Recycling significantly reduces carbon footprint and material waste. 📌 𝐓𝐲𝐫𝐞 𝐑𝐞𝐜𝐲𝐜𝐥𝐢𝐧𝐠 𝐏𝐫𝐨𝐜𝐞𝐬𝐬: ✓. Collection and transportation to authorized recycling facilities. ✓. Shredding into chips followed by steel and fiber separation. ✓. Granulation into crumb rubber of varying sizes. ✓. Pyrolysis - to recover oil, gas, and carbon black. 📌 𝐏𝐫𝐞-𝐏𝐫𝐨𝐜𝐞𝐬𝐬𝐢𝐧𝐠 & 𝐒𝐞𝐠𝐫𝐞𝐠𝐚𝐭𝐢𝐨𝐧: ✓. Removal of contaminants and foreign materials. ✓. Magnetic separation of embedded steel wires. ✓. Fiber extraction for clean rubber output. ✓. Quality classification based on end-use requirements. 📌 𝐄𝐧𝐠𝐢𝐧𝐞𝐞𝐫𝐢𝐧𝐠 𝐀𝐩𝐩𝐥𝐢𝐜𝐚𝐭𝐢𝐨𝐧𝐬: ✓. Rubberized asphalt for flexible and durable pavements. ✓. Shock-absorbing layers in playgrounds and sports fields. ✓. Lightweight fill material in embankments and retaining structures. ✓. Landscaping elements such as mulch and erosion control barriers. 📌 𝐄𝐜𝐨𝐧𝐨𝐦𝐢𝐜 & 𝐒𝐮𝐬𝐭𝐚𝐢𝐧𝐚𝐛𝐥𝐞 𝐁𝐞𝐧𝐞𝐟𝐢𝐭𝐬: ✓. Reduction in raw material consumption and import costs. ✓. Lower lifecycle cost of roads due to enhanced durability. ✓. Generation of green jobs and circular economy growth. ✓. Energy recovery from pyrolysis contributes to resource efficiency. 📌 𝐐𝐮𝐚𝐥𝐢𝐭𝐲 𝐂𝐨𝐧𝐭𝐫𝐨𝐥 & 𝐒𝐭𝐚𝐧𝐝𝐚𝐫𝐝𝐬: ✓. Gradation control of crumb rubber for asphalt mixes. ✓. Performance testing (rutting, fatigue, skid resistance). ✓. Compliance with environmental and municipal regulations. ✓. Continuous monitoring of emissions in thermal processes. 📌 𝐄𝐧𝐯𝐢𝐫𝐨𝐧𝐦𝐞𝐧𝐭𝐚𝐥 & 𝐒𝐭𝐫𝐮𝐜𝐭𝐮𝐫𝐚𝐥 𝐎𝐮𝐭𝐜𝐨𝐦𝐞: ✓. Significant reduction in landfill waste and environmental hazards. ✓. Improved pavement performance—noise reduction and crack resistance. ✓. Enhanced sustainability rating of infrastructure projects. ✓. Conversion of waste into a valuable engineering resources.

Airbus just proved that aerospace composites can be recycled and flown again. This year’s JEC Circularity Award went to a consortium led by Airbus, together with Toray Advanced Composites, DAHER, and TARMAC AEROSAVE. An end-of-life thermoplastic composite part from an A380 was repurposed into a certified structural component for an A320neo. Not a lab demonstrator. Not a cosmetic panel. A flying part. Key facts: – 𝗠𝗮𝘁𝗲𝗿𝗶𝗮𝗹: Toray Cetex thermoplastic composite (carbon fiber / PPS) – 𝗦𝗼𝘂𝗿𝗰𝗲: decommissioned A380 parts, ~20 years in service – 𝗣𝗿𝗼𝗰𝗲𝘀𝘀: re-forming via stamp forming – 𝗢𝘂𝘁𝗽𝘂𝘁: A320neo pylon cowls, flight-certified – 𝗤𝘂𝗮𝗹𝗶𝘁𝘆: mechanically indistinguishable from brand-new One detail matters more than most people realize. The original A380 panel was larger and differently shaped. During re-processing, it was not shredded. Fiber continuity, orientation, and layup were largely preserved. The result is a smaller panel of the same type, made from the same material system. This is not how metals are reused. Metals age through corrosion, fatigue, plastic deformation, and microstructural changes. In aerospace, they are recycled by melting and re-alloying, not by trimming and reshaping flying parts. Composites age differently. They don’t corrode, and their chemistry is relatively stable. They can develop internal defects, but these can be inspected, characterized, and managed. What this project shows is not that defects disappear, but that a thermoplastic composite structure can be trimmed, re-formed, inspected, and re-qualified, while preserving structural requirements. That point matters more than all the sustainability language combined. Thermoset composites usually fail here because they cannot be recycled into new structural parts without adding virgin material. Typical routes remove the matrix (e.g. pyrolysis), recovering only fibers, often at lower grade. Here, the part is not decomposed. No virgin material is added. The recycled component remains within the same structural requirements. Thermoplastics enable this because they can be reheated and reshaped while retaining the entire original material system, not just acceptable performance values. What makes this credible is the system, not just the material. Tarmac Aerosave handled end-of-life recovery. Toray supported material characterization and re-forming. Daher industrialized manufacturing. Airbus validated and flew the result. Circularity only works when the full chain is involved. The A380 alone contains over 10,000 flying thermoplastic composite parts. If even a fraction re-enter production, this changes lifecycle cost, sourcing strategies, and future design logic. This isn’t a sustainability promise. It’s old parts, real aircraft, and certified structures flying again. If you work on composite lifecycle or certification: where do you see thermoplastic reuse fitting into future programs?

What is TerraTimber? An innovative method for the digital upcycling of waste wood to create circular construction systems enabling the sustainable transformation of reclaimed materials into structural elements. This approach utilizes computational tools and Augmented Reality (AR) fabrication processes to manage the complexity of diverse, non-standard waste wood materials. Starting from the generation of digital inventories through image processing, the wood pieces are then computationally assembled into large structural elements, which are finally physically assembled with nails made of wood and with the aid of AR. Earth is integrated to form a hybrid material system, enabling the construction of sustainable floor slabs from natural and recyclable materials. 📐 Karlsruhe Institute of Technology (KIT) - Department of Architecture, Professur Digital Design and Fabrication (DDF), Professur Design of Structures (dos)

In an innovative step toward sustainable construction, Germany is turning old ceramic toilets and sanitary waste into a valuable resource for building stronger roads. Instead of sending damaged sinks, tiles, and toilets to landfills, these discarded materials are crushed into fine particles and reused as a filler in asphalt and road foundations. Ceramic waste is extremely durable, heat-resistant, and hard-wearing—qualities that make it ideal for infrastructure projects. When mixed into asphalt or used as a base layer beneath roads, the crushed ceramic improves structural strength and longevity. This helps roads withstand heavy traffic, temperature changes, and long-term wear more effectively than traditional materials alone. The environmental benefits are just as significant. Construction and demolition waste make up a large portion of landfill volume, and ceramics are particularly difficult to decompose. By recycling sanitary ceramics into road materials, Germany is reducing landfill pressure, conserving natural resources like sand and gravel, and lowering the environmental footprint of construction projects. This approach also supports the circular economy, where waste from one sector becomes a resource for another. Instead of extracting new raw materials from the environment, existing materials are reused, cutting energy consumption and reducing emissions associated with mining and transport. Cities and infrastructure planners across Europe are watching this model closely as they search for smarter, greener ways to manage waste while improving public infrastructure. With growing urban populations and increasing demand for sustainable development, innovative recycling solutions like this are becoming essential. Germany’s ceramic recycling initiative proves that even everyday waste can play a role in building stronger, more resilient infrastructure. It’s a powerful example of how smart engineering and environmental responsibility can work together to create cleaner cities and a more sustainable future. #CircularEconomy #SustainableConstruction #RecyclingInnovation #GreenInfrastructure #collected

Wind Turbine Blade Disposal Were Supposed to Be the Price We Paid for Green Energy. That Equation Just Changed.   By 2050, 43 million metric tons of wind turbine blades will reach end-of-life. These aren’t biodegradable, nor are they easily recyclable. They’re made from hyper-durable composites—mostly glass or carbon fiber locked in a near-indestructible epoxy matrix. Until now, “recycling” meant landfilling, incineration, or grinding into low-value filler. In other words, not recycling at all. That’s the problem with high-performance composites: what makes them strong also makes them stubborn. But a Danish research team, in collaboration with Vestas, may have quietly changed the rules of the game. Instead of smashing composites apart, they used a biomimetic molecular trick: embedding a tiny dose of the amino acid cystine during epoxy curing. This introduces reversible cross-links—chemically engineered escape hatches. With a mild pH switch and common solvents, the matrix softens. The resin dissolves. The fibers emerge—fully intact. This isn’t incremental. This is chemical circularity—where end-of-life becomes a design parameter, not an afterthought. Why this matters to investors: 🧠 Defensibility: Embedding recyclability into the polymer backbone is a platform technology, not a patch. 🌍 Market Pull: OEMs are under pressure to deliver “zero-waste” wind energy. The EU, for instance, is already moving to ban blade landfilling. 📈 Scale: Composite waste isn’t just a wind problem—it’s aerospace, automotive, even consumer goods. Solving it opens a multi-billion-dollar materials recovery market. The thesis: Mechanical recycling is yesterday’s compromise. True circularity will come from programmable materials—where chemical structure encodes end-of-life behavior. And that unlocks a new category of climate tech: regenerative materials systems. I believe this shift creates enormous whitespace for deep tech investment. Not just in blade recycling—but in the reinvention of thermosets themselves. 🔍 I’m tracking this space closely and advising across materials startups. If you're an investor exploring new materials platforms, let’s talk.

♻️ From Bathrooms to Autobahns: Germany’s Circular Road Innovation Germany is turning an unlikely waste stream into a high-performance infrastructure solution — recycled ceramic toilets. Decommissioned bathroom fixtures, once headed for landfills, are now crushed into fine, angular aggregates and blended into asphalt mixes. Made from vitrified clay, these ceramic particles bond exceptionally well with conventional paving materials, enhancing durability, texture, and skid resistance. This innovation solves two challenges simultaneously: Construction waste reduction Improved road performance Unlike traditional quarried fillers, recycled ceramics offer comparable density and superior wear resistance. Their sharp edges improve asphalt grip — a critical advantage for Germany’s high-speed road networks. The process is both systematic and scalable: ✔️ Toilets are collected, sanitized, and dismantled ✔️ Metals are removed ✔️ Ceramics are crushed into gravel-sized aggregates ✔️ The reclaimed material is reused in roads, sidewalks, and bike lanes What was once a symbol of disposal now supports daily mobility — a powerful example of circular design in action. Germany’s ceramic roads remind us that sustainability isn’t always about new materials — sometimes, it’s about seeing new value in what’s already broken. Follow: Abhishek Agrawal for more inspiring insights. #CircularEconomy #SustainableInfrastructure #WasteToResource #UrbanInnovation #GreenConstruction #CircularDesign #RecycledMaterials #RoadEngineering #SustainabilityInAction #ClimateSmartInfrastructure

How do we turn demolition waste and CO₂ into tomorrow’s building materials? Our newly published state-of-the-art report explores just that: https://lnkd.in/ec7c5sUw This paper synthesizes global research efforts—from academia to industry—on: • Selective separation of demolished concrete into reusable fractions • CO₂ mineralization in recycled cementitious materials • Composite cements with novel supplementary cementitious materials It’s not just about what’s possible in the lab—it’s about what’s already happening in the field. At Heidelberg Materials, these concepts are being scaled through the #ReConcrete project, a cross-functional initiative that bridges scientific innovation with industrial implementation. From recycling and carbonation plants in Poland to the R&D lab in Leimen, we’re engineering solutions that work at scale—as Dr Dominik von Achten recently emphasized: https://lnkd.in/eYeyhaiC. This publication is a snapshot of where we stand as a community—researchers, engineers, and industry—on the path to circular concrete. If you're working on mineralization, recycling, or SCMs, I’d love to hear your perspective. It’s a collective effort, and I’m proud to do this work with Jan Skocek, Wolfgang Dienemann and may other colleagues from Heidelberg Materials and collaborators from the universities!

A house near Hanover, Germany was constructed using almost 100% secondhand materials ♻️ Building with reclaimed materials has three common challenges: 1. Finding materials in good condition and in the right quantity 2. Ensuring those materials meet current building codes 3. Finding an architect/builder that is committed to reuse and pushing conventional design boundaries The architecture firm CITYFÖRSTER addressed all three by designing a house almost entirely from reclaimed, recycled, and upcycled materials. Some examples: 🖼️ The aluminum windows and fiber cement panels were salvaged from a nearby youth center that was renovated into social housing 🏸 The wooden strips framing the entrance once served as sauna benches in a local sports club 🎨 The green and blue facade glass panels were salvaged from an old paint shop that was demolished This project is a great prototype for "design follows availability," or a commitment to using materials that already exist in a nearby city or region. This approach encourages us to rethink how we value materials in the built environment -- before, during, and after their first lifecycle. Photos from the architecture firm's project feature -- link in comments! 👋 I talk about circular economy in the built environment, including cultural heritage, workforce development, and affordable housing. Follow for more case studies! #circulareconomy #greenbuilding #sustainability #sustainableconstruction #decarbonisation #climateheritage #embodiedcarbon