title: A three-dimensional flexible microprobe array for neural recording assembled through electrostatic actuation.
abstract: We designed, fabricated and tested a novel three-dimensional flexible microprobe to record neural signals of a lateral giant nerve fiber of the escape circuit of an American crayfish. An electrostatic actuation folded planar probes into three-dimensional neural probes with arbitrary orientations for neuroscientific applications. A batch assembly based on electrostatic forces simplified the fabrication and was non-toxic. A novel fabrication for these three-dimensional flexible probes used SU-8 and Parylene technology. The mechanical strength of the neural probe was great enough to penetrate into a bio-gel. A flexible probe both decreased the micromotion and alleviated tissue encapsulation of the implant caused by chronic inflammation of tissue when an animal breathes or moves. The cortex consisted of six horizontal layers, and the neurons of the cortex were arranged in vertical structures; the three-dimensional microelectrode arrays were suitable to investigate the cooperative activity for neurons in horizontal separate layers and in vertical cortical columns. With this flexible probe we recorded neural signals of a lateral giant cell from an American crayfish. The response amplitude of action potentials was about 343 µV during 1 ms period; the average recorded data had a ratio of signal to noise as great as 30.22 ± 3.58 dB. The improved performance of this electrode made feasible the separation of neural signals according to their distinct shapes. The cytotoxicity indicated a satisfactory biocompatibility and non-toxicity of the flexible device fabricated in this work.
authors: Institute of NanoEngineering and MicroSystems, National Tsing Hua University, Hsinchu, 30013, Taiwan.
authors: Chang-Hsiao
authors: CH
authors: Chen
authors: Shih-Chang
authors: SC
authors: Chuang
authors: Huan-Chieh
authors: HC
authors: Su
authors: Wei-Lun
authors: WL
authors: Hsu
authors: Tri-Rung
authors: TR
authors: Yew
authors: Yen-Chung
authors: YC
authors: Chang
authors: Shih-Rung
authors: SR
authors: Yeh
authors: Da-Jeng
authors: DJ
authors: Yao
mesh_terms: D000818:Animals; D003400:Astacoidea; D002452:Cell Count; D004567:Electrodes, Implanted; D055724:Electrophysiological Phenomena / Q000502:physiology; D004594:Electrophysiology / Q000295:instrumentation*; D004867:Equipment Design; D006046:Gold; D009412:Nerve Fibers / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000502:physiology; D018583:Pliability; D033081:Shear Strength; D012815:Signal Processing, Computer-Assisted; D055672:Static Electricity
chemical_list: D006046:Gold