Highly stretchable and soft microelectrode arrays for free-form organoids

Abstract

Understanding brain circuits is important to develop treatments for brain disorders or to find mechanisms of brain diseases and in vivo and in vitro experiments are conducted to measure neural activity of stimulated specimens. Due to in vitro disease models showed lack of complexity than human brains, brain organoids were developed to mimic complex structure and various functions of the brains. However, current neural recording devices are not suitable to the brain organoids due to its invasiveness and limited recording areas. In this dissertation paper, a novel microelectrode array (MEA) to read biological signals of the brain organoids over a large area was proposed. Serpentine shape patterned flexible and transparent polyimide increased stretchability and bilayer structure have contact with both base and side area of the organoids. Ex vivo mouse brain was placed on top of the MEA and neural signals were recorded successfully, but there is a limitation that could not be measured in the presence of media due to poor contact between the electrodes and the brain.