The ability to 3D print soft materials with integrated strain sensors enables significant flexibility for the design and fabrication of soft robots. Hydrogels provide an interesting alternative to traditional soft robot materials, allowing for more varied fabrication techniques. In this work, we investigate the 3D printing of a gelatin-glycerol hydrogel, where transglutaminase is used to catalyse the crosslinking of the hydrogel such that its material properties can be controlled for 3D printing. By including electron-conductive elements (aqueous carbon black) in the hydrogel we can create highly flexible and linear soft strain sensors. We present a first investigation into adapting a desktop 3D printer and optimizing its control parameters to fabricate sensorized 2D and 3D structures which can undergo $>$ 300% strain and show a response to strain which is highly linear and synchronous. To demonstrate the capabilities of this material and fabrication approach, we produce some example 2D and 3D structures and show their sensing capabilities.

中文翻译：

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适用于多材料软结构的3D可打印传感软明胶水凝胶

具有集成应变传感器的3D打印软材料的能力为软机器人的设计和制造提供了极大的灵活性。水凝胶为传统的软机器人材料提供了一种有趣的替代方法，从而允许使用更多不同的制造技术。在这项工作中，我们研究了明胶-甘油水凝胶的3D打印，其中转谷氨酰胺酶用于催化水凝胶的交联，从而可以控制其材料特性进行3D打印。通过在水凝胶中包含电子导电元素（碳黑水溶液），我们可以创建高度灵活和线性的线性应变传感器。我们提出了一项关于改装台式机3D打印机并优化其控制参数以制造可感应的2D和3D结构的初步研究。$> $ 300％的应变，并显示出对应变的响应，该响应是高度线性和同步的。为了演示这种材料和制造方法的功能，我们提供了一些示例2D和3D结构并显示了它们的感测能力。