Jeon, Myounggun Cho, Jeiwon Kim, Yun Kyung Jung, Dahee Yoon, Eui-Sung Shin, Sehyun Cho, Il-Joo 2024-01-20T10:32:02Z 2024-01-20T10:32:02Z 2021-09-05 2014-02 0960-1317 https://pubs.kist.re.kr/handle/201004/127137 This paper presents a flexible microelectromechanical systems (MEMS) neural probe that minimizes neuron damage and immune response, suitable for chronic recording applications. MEMS neural probes with various features such as high electrode densities have been actively investigated for neuron stimulation and recording to study brain functions. However, successful recording of neural signals in chronic application using rigid silicon probes still remains challenging because of cell death and macrophages accumulated around the electrodes over time from continuous brain movement. Thus, in this paper, we propose a new flexible MEMS neural probe that consists of two segments: a polyimide-based, flexible segment for connection and a rigid segment composed of thin silicon for insertion. While the flexible connection segment is designed to reduce the long-term chronic neuron damage, the thin insertion segment is designed to minimize the brain damage during the insertion process. The proposed flexible neural probe was successfully fabricated using the MEMS process on a silicon on insulator wafer. For a successful insertion, a biodegradable sucrose gel is coated on the flexible segment to temporarily increase the probe stiffness to prevent buckling. After the insertion, the sucrose gel dissolves inside the brain exposing the polyimide probe. By performing an insertion test, we confirm that the flexible probe has enough stiffness. In addition, by monitoring immune responses and brain histology, we successfully demonstrate that the proposed flexible neural probe incurs fivefold less neural damage than that incurred by a conventional silicon neural probe. Therefore, the presented flexible neural probe is a promising candidate for recording stable neural signals for long-time chronic applications. English IOP PUBLISHING LTD INTRACORTICAL ELECTRODE ARRAY MICROELECTRODE ARRAY DELIVERY BIOCOMPATIBILITY MICROSYSTEMS RECORDINGS INTERFACES TISSUE Partially flexible MEMS neural probe composed of polyimide and sucrose gel for reducing brain damage during and after implantation Article 10.1088/0960-1317/24/2/025010 1 JOURNAL OF MICROMECHANICS AND MICROENGINEERING, v.24, no.2 JOURNAL OF MICROMECHANICS AND MICROENGINEERING 24 2 scie scopus 000332711200010 2-s2.0-84893116769 Engineering, Electrical & Electronic Nanoscience & Nanotechnology Instruments & Instrumentation Physics, Applied Engineering Science & Technology - Other Topics Instruments & Instrumentation Physics Article INTRACORTICAL ELECTRODE ARRAY MICROELECTRODE ARRAY DELIVERY BIOCOMPATIBILITY MICROSYSTEMS RECORDINGS INTERFACES TISSUE flexible probe MEMS neural probe neuron damage polyimide sucrose gel