Mushroom Toilet Paper 馬桶上的我，發現衛生紙還沒長好   

An average person uses approximately 5.5 metres of toilet paper per day, finishing one roll in about four days. Pink oyster mushrooms (Pleurotus djamor) thrive in warm, humid, and dark environments between 20–33°C. They can grow year-round and are typically ready for harvest within two to three weeks. Since their ideal growing conditions are similar to those found in bathrooms, and their growth is faster and more consistent than that of trees, pink oyster mushrooms were selected as the material for this new form of toilet paper.

Although mushrooms grow considerably faster than trees, their natural growth rate is still not fast enough to keep pace with the consumption of one roll of toilet paper every four days. To address this limitation, the project draws inspiration from the internodal growth of bamboo and imagines transferring genetic traits associated with whole-genome duplication (WGD) from bamboo into pink oyster mushrooms. This fictional fast-growing mushroom is named “Rapidus.”

During its early growth stage, Rapidus develops nodes similar to those of bamboo. Each node contains intercalary meristematic tissue, allowing the mushroom to grow rapidly during its peak growth period. Its segmented structure also allows it to separate naturally into sections, similar to the perforated sheets of a conventional toilet paper roll.

The team also designed a dedicated toilet paper holder to support the growth and everyday use of Rapidus. The central core of the holder is made from a sawdust-based growing medium suitable for the mushroom and is equipped with an automatic winding mechanism. By monitoring the weight of the growing mushroom, the mechanism triggers the core to rotate and gradually wind the material around it. Once Rapidus has fully grown, it forms a complete roll of toilet paper ready for use.

馬桶上的我，發現衛生紙還沒長好

人一天平均約用掉5.5公尺的廁用捲筒衛生紙，大約四天會用完一捲。粉紅側耳菇（玫瑰菇）適合生長在20~33℃陰暗濕熱的環境，一年四季皆可出菇，二至三週即可採收。由於菇的生長環境與廁所相似，且生長模式比樹木快且穩定，而在菇類中又以粉紅側耳菇生長最為快速，因此選擇以粉紅側耳菇作為新型態衛生紙的材料。

雖然菇類生長相對樹木快速，但仍不足人在四天內用完一捲衛生紙的速度。為了克服生長速度的問題，參考竹子節間生長的模式，將竹子的WGD基因（全基因组加倍基因）轉殖入粉紅側耳菇中，而這種能快速生長的菇類名為「迅菇」。迅菇生長初期會與竹子一樣長出節點，各節點皆有居間分生組織，在生長高峰期時便能快速生長，且自動分段，如同廁所捲筒衛生紙般能分段取用。

本團隊也開發了一款適合迅菇衛生紙生長的衛生紙架，以配合這款新型態衛生紙在生活中的應用。此衛生紙架的軸是適合迅菇生長的木屑，且配有自動捲軸器，透過量測香菇的重量便發觸發軸的轉動，讓迅菇生長完成後即是一捲衛生紙。