牆壁發電還能防火？海藻泡棉做到了！

安裝太陽能板不再是唯一將綠能融入日常生活的方式。由西班牙材料科學研究所（ICMM-CSIC）領軍、攜手南韓研究機構的國際團隊，近日研發出一款看似普通包裝泡棉的創新材料，卻同時具備三大功能：隔熱、防火與將壓力轉換為電力的自發電能力，堪稱智慧建材的一大突破。

A breakthrough in smart building materials may soon change how we think about energy and safety in our homes. An international team led by Spain’s Institute of Materials Science of Madrid (ICMM-CSIC), in collaboration with South Korean researchers, has developed an innovative material that resembles ordinary packaging foam but offers three key functions: thermal insulation, fire resistance, and self-generated electricity through pressure. This multifunctional foam represents a major advance in sustainable and intelligent construction.

這款泡棉的成分以天然的褐藻多醣（海藻酸鈉）為基底，搭配奈米級的碳化鈦片（MXene）混合成漿，再透過冷凍乾燥技術，製成與保麗龍相仿輕盈的多孔泡棉。

三效合一：隔熱、防火、發電

Triple Function: Insulation, Fire Resistance, and Electricity Generation

The foam is primarily composed of natural sodium alginate, a polysaccharide derived from brown seaweed, and reinforced with nanoscale titanium carbide (MXene) flakes. These ingredients are blended into a slurry and freeze-dried to create a lightweight, porous foam similar in texture to polystyrene.

研究團隊指出，實驗樣品的密度僅 0.02 公克/立方公分，導熱係數為 0.062 W/m·K，比市售的聚氨酯隔熱板提升 15% 的隔熱效率。當泡棉受到踩踏或擠壓時，內部因接觸摩擦而產生壓電效應（TENG），最高可產生達 380 伏特的瞬間電壓，足以點亮 20 顆 LED 燈。

泡棉同時具備出色的防火性能。研究顯示，即便用 1600°F（約870°C）的高溫火焰直噴，材料也能在兩秒內自行熄滅，且不產生有毒煙霧，內建 LED 警示系統也會即時閃爍提醒。

The resulting material has a density of only 0.02 g/cm³ and a thermal conductivity of 0.062 W/m·K, making it 15% more efficient than commercial polyurethane insulation boards. When the foam is stepped on or compressed, the internal friction triggers a triboelectric nanogenerator (TENG) effect, producing instant voltages up to 380 volts, sufficient to power 20 LED lights.

材料結構與機制

海藻酸鈉常見於食品增稠劑或醫療敷料，在此應用中則發揮天然耐燃特性與形成冰模板孔隙結構的作用，有效減緩熱傳導。奈米 MXene 片則遍布泡棉內部，形成導電網絡，壓縮時產生電力，同時當溫度超過 200°C 時，其電阻迅速下降，可作為熱警報器使用，無需外接感測元件。

應用潛力與永續優勢

此材料若能量產，未來可應用於多種高潛力場域，包括：

雖然海藻在製程中已轉化為穩定結構，不具生物活性，但最終仍可生物分解、燃燒後也只產生無毒灰燼，遠優於含溴阻燃泡棉。另一方面，海藻養殖可吸收大量二氧化碳，且不需施肥或佔用土地。儘管 MXene 製造能耗較高，但其可再利用為二氧化鈦顏料，部分閉合循環。

The foam also demonstrates excellent fire resistance. Tests show that even under direct exposure to 1600°F (≈870°C) flames, it can self-extinguish within two seconds without emitting toxic smoke. It is also equipped with an embedded LED warning system that flashes instantly in response to heat.

Material Structure and Mechanism

Sodium alginate, commonly used in food thickeners and medical dressings, serves here as a flame-retardant binder that also forms the foam’s porous ice-template structure - effectively slowing heat transfer. Dispersed throughout the foam, the MXene nanosheets create a conductive network that generates electricity under pressure. When exposed to temperatures above 200°C, MXene’s resistance drops sharply, allowing it to function as a thermal alarm - without the need for external sensors.

Potential Applications and Sustainability Advantages

If commercialized, this smart foam could be deployed in a range of high-impact sectors:

市場競爭力與前景

傳統聚氨酯板價格約為每公斤 1 美元，但需額外添加溴系阻燃劑，且在 350°C 時會融化燃燒；矽氣凝膠雖保溫效果佳，但造價高達每平方公尺 50 美元，且脆弱易碎。

相比之下，這款海藻–MXene 泡棉的未來單價有望壓低至每平方公尺 10 美元，不僅重量更輕，還內建發電與警報功能，大幅提升價值與應用彈性。

Though the seaweed component becomes inert after processing, the material remains biodegradable and produces only non-toxic ash when incinerated - offering a safer alternative to brominated flame-retardant foams. Moreover, seaweed farming absorbs CO₂, requires no fertilizer or land, and supports regenerative aquaculture.

While MXene production is relatively energy-intensive, the material can be recycled into titanium dioxide pigments, allowing for partial circularity.

Market Competitiveness and Outlook

Conventional polyurethane insulation boards cost around $1 per kg but require brominated flame retardants and melt at 350°C. Aerogels offer excellent insulation but are fragile and priced up to $50 per square meter.

In contrast, the new seaweed–MXene foam is projected to reach a future cost of just $10 per square meter. It is lighter, safer, and comes with built-in electricity generation and fire warning capabilities, greatly increasing its value and versatility.

目前已有兩個產業領域表達合作意向：一是歐洲模組化住宅建商，預計於 2026 年進行牆體實證測試；另一是美國加州的電池模組開發商，評估用於鋰電池間的防火隔板。

Two industries have already expressed interest in collaborating:

從壽司海藻到未來建材

From Sushi Seaweed to the Future of Smart Buildings

十年前，海藻只存在於壽司中，MXene 也僅出現在實驗室期刊裡；如今兩者結合，為未來建築與交通工具提供了防火、隔熱、發電兼顧永續的可能性。若能突破成本與量產門檻，這種安靜地藏在牆後的「智慧泡棉」，將有望比屋頂太陽能板更早警示火災、供電給感測器，改寫智慧建築的新篇章。

A decade ago, seaweed was mostly confined to sushi rolls, and MXene was limited to lab journals. Now, their combination may shape the future of buildings and transportation - offering fire resistance, insulation, power generation, and sustainability in one elegant solution. If the barriers of cost and scalability can be overcome, this silent “smart foam” hidden within walls could one day alert fires before smoke detectors, power embedded sensors, and outperform rooftop solar panels in redefining smart, sustainable architecture.