Microscale needle-electrode devices offer neuronal signal recording capability in brain tissue; however, using needles of smaller geometry to minimize tissue damage causes degradation of electrical properties, including high electrical impedance and low signal-to-noise ratio (SNR) recording. We overcome these limitations using a device assembly technique that uses a single needle-topped amplifier package, called STACK, within a device of ∼1 × 1 mm². Based on silicon (Si) growth technology, a <3-µm-tip-diameter, 400-µm-length needle electrode was fabricated on a Si block as the module. The high electrical impedance characteristics of the needle electrode were improved by stacking it on the other module of the amplifier. The STACK device exhibited a voltage gain of >0.98 (−0.175 dB), enabling recording of the local field potential and action potentials from the mouse brain in vivo with an improved SNR of 6.2. Additionally, the device allowed us to use a Bluetooth module to demonstrate wireless recording of these neuronal signals; the chronic experiment was also conducted using STACK-implanted mice.

微型针电极装置提供脑组织中的神经元信号记录能力；然而，使用较小几何形状的针来最大程度地减少组织损伤会导致电性能下降，包括高电阻抗和低信噪比（SNR）记录。^{我们使用一种设备组装技术克服了这些限制，该技术在~1 × 1 mm 2}的设备内使用单个针顶放大器封装（称为 STACK）。基于硅 (Si) 生长技术，在 Si 块上制造了尖端直径 <3 µm、长度 400 µm 的针电极作为模块。通过将针电极堆叠在放大器的另一个模块上，改善了针电极的高电阻抗特性。STACK 设备的电压增益>0.98 (−0.175 dB)，能够记录体内小鼠大脑的局部场电位和动作电位，并将信噪比提高到 6.2。此外，该设备允许我们使用蓝牙模块来演示这些神经元信号的无线记录；这项长期实验也是使用植入 STACK 的小鼠进行的。