The demand for multifunctional neural interfaces has grown due to the need to provide a better understanding of biological mechanisms related to neurological diseases and neural networks. Direct intracerebral drug injection using microfluidic neural interfaces is an effective way to deliver drugs to the brain, and it expands the utility of drugs by bypassing the blood–brain barrier (BBB). In addition, uses of implantable neural interfacing devices have been challenging due to inevitable acute and chronic tissue responses around the electrodes, pointing to a critical issue still to be overcome. Although neural interfaces comprised of a collection of microneedles in an array have been used for various applications, it has been challenging to integrate microfluidic channels with them due to their characteristic three-dimensional structures, which differ from two-dimensionally fabricated shank-type neural probes. Here we present a method to provide such three-dimensional needle-type arrays with chemical delivery functionality. We fabricated a microfluidic interconnection cable (µFIC) and integrated it with a flexible penetrating microelectrode array (FPMA) that has a 3-dimensional structure comprised of silicon microneedle electrodes supported by a flexible array base. We successfully demonstrated chemical delivery through the developed device by recording neural signals acutely from in vivo brains before and after KCl injection. This suggests the potential of the developed microfluidic neural interface to contribute to neuroscience research by providing simultaneous signal recording and chemical delivery capabilities.

由于需要更好地理解与神经系统疾病和神经网络相关的生物机制，对多功能神经接口的需求不断增长。使用微流控神经接口直接脑内药物注射是将药物输送到大脑的有效方法，它通过绕过血脑屏障（BBB）扩大了药物的效用。此外，由于电极周围不可避免的急性和慢性组织反应，植入式神经接口装置的使用一直具有挑战性，这表明仍有一个需要克服的关键问题。尽管由阵列中的微针集合组成的神经接口已用于各种应用，但由于其特征性的三维结构（与二维制造的柄型神经探针不同），将微流体通道与其集成一直具有挑战性。 。在这里，我们提出了一种为这种三维针型阵列提供化学输送功能的方法。我们制造了微流体互连电缆 (μFIC) 并将其与柔性穿透微电极阵列 (FPMA) 集成，该阵列具有由柔性阵列底座支撑的硅微针电极组成的 3 维结构。我们通过在 KCl 注射前后敏锐记录体内大脑的神经信号，成功地证明了通过所开发的设备进行化学输送。这表明所开发的微流体神经接口有潜力通过提供同步信号记录和化学传递能力来促进神经科学研究。