Development and evaluation of tube-shaped neural probe with working channel

Recent Progress on Non-Conventional Microfabricated Probes for the Chronic Recording of Cortical Neural Activity

“…Various types of brain probes with tube- or cylindrical structures have been demonstrated, offering several advantages over conventional shank-type probes. The hollow core of the tube structure can be utilized to add multi-functionality by inserting optic fibers or flowing drugs through the channel without increasing the probe dimension [ 145 , 146 , 147 , 148 , 149 , 150 ]. This type can also be exploited to control the flexibility of the probe by making it rigid with mechanical support during the insertion process and retuning it to highly flexible state after positioned in the brain and guide removal [ 146 , 149 ].…”

“…The hollow core of the tube structure can be utilized to add multi-functionality by inserting optic fibers or flowing drugs through the channel without increasing the probe dimension [ 145 , 146 , 147 , 148 , 149 , 150 ]. This type can also be exploited to control the flexibility of the probe by making it rigid with mechanical support during the insertion process and retuning it to highly flexible state after positioned in the brain and guide removal [ 146 , 149 ]. Moreover, three-dimensional probing and high spatial selectivity can be achieved by placing electrode sites around the circumferential surface of the tube [ 142 , 148 , 150 ].…”

“…Fabrication techniques of three-dimensional tubes or cylindrical structures can generally be categorized into three types: creating a conventional planar thin-film array and wrapping it around a shank [ 142 , 143 , 144 , 150 ], direct patterning onto a curved cylindrical surface using customized non-planar microfabrication tools [ 145 , 146 , 147 , 148 ], or building a three-dimensional tube structure starting from a planar substrate by sequential deposition and etching [ 149 ]. A polyimide-based thin-film electrode array fabricated by conventional microfabrication process was wrapped around and fixed onto a polyurethane shaft at a 240-degree angle by thermal forming of a thin film array between a pair of matched molds [ 142 ].…”

“…Various research groups have addressed these issues by introducing unique features which are added to conventional shank-type cortical arrays through specially devised microfabrication techniques. As illustrated in Figure 1B, these efforts have resulted in a variety of microelectrode arrays featuring various non-conventional characteristics, including: (1) multi-sided arrays to avoid shielding and increase the recording volume [132,133,134,135,136,137,138,139,140,141]; (2) tube-type or cylindrical probes for three-dimensional (3D) recording, deep insertion and multi-modality capabilities [142,143,144,145,146,147,148,149,150]; (3) folded arrays for high conformability and 3D recording [151,152,153,154]; (4) self-softening or self-deployable probes for minimized tissue damage and an extension of the recording site beyond the gliosis [155,156,157,158,159,160,161,162,163,164,165,166,167,168]; (5) mesh- or thread-like arrays to minimize glial scarring and immune response levels [169,170,171,172,173,174,175,176,177,178,179,180,181]; (6) nanostructured probes to reduce the immune response [182,183,184,…”

Flexible Tube-Shaped Neural Probe for Recording and Optical Stimulation of Neurons at Arbitrary Depths

“…(15) The probe has a working channel. When it is inserted into the brain through the dura mater, it is stiff because a metal needle is set in the working channel.…”