Novel four-sided neural probe fabricated by a thermal lamination process of polymer films

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

“…The side electrode had the unique feature of three exposed sides. A four-sided depth probe was developed by Shin et al, having electrode sites on all four sides of its rectangular probe shank based on liquid crystal polymer (LCP), as shown in Figure 2D [141]. Four metal patterned LCP layers for the top, bottom, and two side electrodes were stacked and thermally laminated together with cover LCP layers.…”

“…The thermoplastic properties of LCP were utilized to create a multilayered substrate simply through single-step thermal lamination process enabling high scalability of channel density. While these multisided probes have been verified in animal experiments using rats [133,135,140], mice [141], and guinea pigs [136,137], their use is not limited to small animals but could be applied in large animals or clinical trials in the future studies given the shape of the shank is not very different from the conventional Michigan arrays.…”

“…Featured multi-sided probes: ( A ) double-sided, transparent polyimide probe (reprinted from [134] with permission from Elsevier, Copyright 2002,); ( B ) double-sided polyimide probe fabricated using silicon posts for opening the electrode on the first metal layer reprinted from [138], with permission from IEEE, © 2012); ( C ) triple-sided parylene probe (reprinted from [140] with permission from Springer Nature Customer Service Centre GmbH); ( D ) four-sided probe based on a liquid crystal polymer (reprinted from [141] with permission from Elsevier, Copyright 2017,); ( E ) Nanoelectronics coating onto optical fiber using Van der Waals interaction (reprinted from [109] with permission from The American Chemical Society, Copyright 2017); ( F ) parylene/polyimide hybrid probe fabricated by direct patterning on a cylindrical surface (reprinted, from [107] with permission from IEEE, © 2017); ( G ) tube-shaped polyimide probe in which a sharp metal needle and optical fiber are embedded (reproduced from [106] with permission from John Wiley & Sons, copyright 2017).…”

“…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,…”

Implantable electrical stimulation bioreactor with liquid crystal polymer based electrodes for enhanced bone regeneration at mandibular large defects in rabbit

“…Recently, liquid crystal polymer (LCP) has been used as a substrate for electrodes in neural prosthetic devices [22,52]. LCP is a biomaterial that has a mechanical strength similar to that of bone, an excellent affinity to bone and can be thermally deformed easily [25].…”