Hydrogels are attracting enormous interests in various applications including electronic skins, tissue engineering, drug delivery, and wearable devices due to their marvelous stretchability, conductivity and ultra-high sensitivity. In the present study, we propose a new type of conductive cross-linked hydrogel fabricated by projection microstereolithography (PμSL) based three-dimensional (3D) printing technique which can be completely degraded when submerged in alkaline within tens of seconds. The tensile strengths and conductivity of hydrogels are tested to demonstrate their great performance of flexibility and conductivity. Moreover, the influences of temperature, pH value and chemical compositions on the conductivity and degradation performance of our printable hydrogels are also explored. Based on the merits of our printable hydrogel, the developed hydrogel sensors promise feasible applications of degradable, highly stretchable and conductive wearable devices and transient electronics. Most significantly, hydrogel circuits can be functionally tailored by alkaline and photocurable precursor of the printable hydrogel within tens of seconds, enabling the ultra-fast programmable human-machine interface to acquire electromyogram (EMG) signals for controlling the fingers of an extraman accurately. The present work opens a gate for designing ultra-fast programmable flexible electronics, transient electronics, human-machine interface, etc. with printed degradable conductive hydrogel.

水凝胶因其出色的可拉伸性、导电性和超高灵敏度而在电子皮肤、组织工程、药物输送和可穿戴设备等各种应用中引起了极大的兴趣。在本研究中，我们提出了一种通过投影微立体光刻法制造的新型导电交联水凝胶（P μ基于 SL) 的三维 (3D) 打印技术，浸入碱性溶液中数十秒内即可完全降解。测试了水凝胶的拉伸强度和导电性，以证明它们具有出色的柔韧性和导电性。此外，还探讨了温度、pH 值和化学成分对可印刷水凝胶的电导率和降解性能的影响。基于我们可打印水凝胶的优点，开发的水凝胶传感器有望在可降解、高度可拉伸和导电的可穿戴设备和瞬态电子设备中得到切实可行的应用。最重要的是，水凝胶电路可以在数十秒内通过可印刷水凝胶的碱性和光固化前体进行功能定制，使超快速可编程人机界面能够获取肌电图 (EMG) 信号，从而准确控制超人的手指。目前的工作为使用印刷可降解导电水凝胶设计超快速可编程柔性电子器件、瞬态电子器件、人机界面等打开了大门。