In this paper, we present a three-layered device for preparation of heterologous core layers linearly aligned in a hydrogel sheet by a simple four-step process without using pumps. Recently, cell-based sensors have been developed for detection of odorant molecules owing to the sensitivity and selectivity of olfactory receptors to chemical substances. To detect various odorant molecules with these sensors, it is necessary to array multiple types of sensor cells expressing different olfactory receptors. We therefore propose a sheet-shaped sensor chip for a sensor-cell array. Previously, hydrogel sheets with heterogeneous cell patterns were produced using microfluidic devices with syringe pump systems, causing loss of both sample volumes and time for settings. Here, we develop a device that enables preparation of hydrogel sheets with a small amount of samples and with a single manual pipette.