CMOS-Compatible Hollow Nanoneedles with Fluidic Connection

Nanoneedles are used for a variety of different biomedical applications such as intracellular injection/extraction and electrical recording. Combining these two capabilities in one device, however, remains challenging. We propose a novel method for fabricating fluidically connected arrays of hollow nanoneedles and characterize the resulting devices regarding their fluidic and electrochemical functionalities. The fabrication process relies solely on complementary metal-oxide-semiconductor (CMOS) compatible and scalable microsystems technology methods. Fluorescence microscopy is used to prove the successful transport of molecules through the passive nanoneedle chips. Electrochemical measurements of ion flows through these devices further confirm both the fluidic contact and the validity of an analytical model used to estimate the electrical resistance of the chips. In total, the presented work paves the way for monolithic integration of fluidic and electrical functionalities for intracellular contacting in a single device. This, in turn, can enable controlled, continuous drug delivery with simultaneous electrical recording on a highly scalable platform.