Fabrication and characterization of implantable silicon neural probe with microfluidic channels

Abstract

In this paper, a silicon-based neural probe with microfluidic channels was developed and evaluated. The probe can deliver chemicals or drugs to the target neurons while simultaneously recording the electrical action of these neurons extracellularly. The probe was fabricated by double-sided deep reactive ion etching (DRIE) from a silicon-on-insulator (SOI) wafer. The fluidic channels were formed with V-shape groove etching on the silicon probe and sealed with silicon nitride and parylene-C. The shank of the probe is 4 mm long and 120 m wide. The thickness of the probe is 100 m. The probe has two fluidic channels and two recording sites. The microfluidic channels can withstand a pressure drop as much as 30 kPa and the flow resistivity of the microfluidic channel is 0.13 L min-1 kPa-1. The typical impedance of the neural electrode is 32.3 k at 1 kHz at room temperature. neural probe, parylene-C, microfluidic channel Citation: Guo K, Pei W H, Li X Q, et al. Fabrication and characterization of implantable silicon neural probe with microfluidic channels. Sci China Tech Sci, 2012, 55: 15,

Overview on Biocompatibilities of Implantable Biomaterials

“…Peripheral venous access had become unsatisfactory in all of patients, and six had required central venous catheterisation [208]. More recently, a silicon-based neural probe with microfluidic channels was developed [209].…”

32-site microelectrode modified with Pt black for neural recording fabricated with thin-film silicon membrane

“…SOI wafer was used in the fabrication process due to its well-defined thickness of device layer, which functioned as the substrate of microelectrode [11]. The device was composed by four layers: the substrate layer which supported all the structures; the lower dielectric layer which insulated the conductive layer from the substrate; the metal layer as the conductive layer and the upper dielectric layer as insulation from outside, which can be seen in Figure 1.…”

Stability Performance Analysis of Various Packaging Materials and Coating Strategies for Chronic Neural Implants under Accelerated, Reactive Aging Tests

“…Among various materials, Parylene-C (PA) is one of the most prevailing packaging materials for biomedical implants [ 14 , 15 , 16 , 17 , 18 ]. SiO 2 [ 19 , 20 , 21 , 22 ], and Si 3 N 4 [ 23 , 24 , 25 ] are usually used as insulating layers in silicon based neural probes as well as an encapsulation protective layer to protect microelectronics from corrosive environments such as body fluids. However, the packaging performances of these films have not been studied systematically.…”