Negative Poisson’s ratio or auxetic foams were fabricated and studied for use in prosthetic applications. A thermomechanical process was used to convert conventional polyurethane (PU) foam into auxetic PU foam. Two types of auxetic PU foams were made using two different volumetric compression ratios, 3.02 and 3.86. Chemical composition analysis showed that chemical structure of the converted auxetic foam remained the same as the conventional PU foam after the thermomechanical process. Compression tests showed that the auxetic foams had higher stiffness than conventional foams, implying that the auxetic foams could be potentially used in seat cushions, shoe soles, and as liners in prosthetic applications. Compression fatigue tests showed that percentage loss in thickness in auxetic foam fabricated using lower compression ratio had loss in thickness that is comparable to conventional foam, whereas auxetic foam fabricated using higher compression ratio had greater loss in thickness. Our study indicates that the auxetic foams made using lower compression ratio need to be further explored for suitability in various rehabilitation applications.

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用于康复应用的拉胀泡沫的制造和测试

负泊松比或拉胀泡沫被制造和研究用于假肢应用。使用热机械工艺将传统聚氨酯 (PU) 泡沫转化为拉胀 PU 泡沫。使用两种不同的体积压缩比 3.02 和 3.86 制造了两种类型的拉胀 PU 泡沫。化学成分分析表明，经过热机械处理后，转化的拉胀泡沫的化学结构与常规PU泡沫保持相同。压缩测试表明，拉胀泡沫比传统泡沫具有更高的刚度，这意味着拉胀泡沫可用于坐垫、鞋底和假肢应用中的衬垫。压缩疲劳试验表明，使用较低压缩比制造的拉胀泡沫的厚度损失百分比与传统泡沫相当，而使用较高压缩比制造的拉胀泡沫具有更大的厚度损失。我们的研究表明，需要进一步探索使用较低压缩比制成的拉胀泡沫在各种康复应用中的适用性。