###### Abstract  
Humans mostly perceive tactile sensations in daily life as a combination of warmth, vibration, and pressure. To understand the complex tactile perception and cognitive processes, in this study, we aimed to develop a multimodal stimulator and investigate changes in neuronal activity. An actuator that can display warmth (W), vibration (V), and pressure (P) on the distal region of the index finger has been developed. Preliminary experiments were conducted with nine subjects. Electroencephalograms were measured for six tactile stimuli--three single stimuli (W, V, and P) and three combination stimuli (W + V, V + P, and W + V + P)--and event-related desynchronization/synchronization (ERD/S) analysis were performed. The actuator can present all kinds of stimuli in the same location and control stimulation parameters quantitatively. For all experiments, there was an ERD in the \(\alpha\) and \(\beta\) bands about 0.5 s after stimulation followed by ERS was observed in the C3 area. The change in the peak-to-peak value was the largest for warmth and the smallest for pressure. In contrast, in the duration of the ERD, W was the shortest and P was the longest. As stimulus presented simultaneously, the ERD became longer in both the alpha and beta bands. In the beta band, the peak of ERD became larger. The developed system was confirmed to be capable of providing valid tactile stimulation, inducing appropriate neuronal activation, and enabling multimodal tactile research. Multimodal tactile stimulator; warmth; vibration; pressure; event-related desynchronization/synchronization 2025 15 7184 202 conducted to add tactile sensation to these technologies to increase realism and provide immersive experiences [5]. Humans primarily use their visual and auditory senses to perceive changes in their environment [6]. For this reason, research has been focused on visual and auditory presentation technology to make spaces and objects feel real such as in virtual reality, augmented reality, and mixed reality [2]. However, as the field of application expands and higher immersion is required, haptics technologies are being introduced to add tactile sensations in addition to visual and auditory sensations [3,5]. Currently, most of them use vibration to add tactile sensation. DC (direct current) motors are mostly used to generate vibration due to their simple configuration, small size, and reproducibility [4, 5, 6, 7, 8]. There have also been attempts to provide pressure sensation using pin arrays or pneumatics, or to display warmth using Peltier elements, but they are rarely used in practical applications. Recently, research has been conducted to provide sustained pressure by changing the plane to convex by electrochemical reaction [9,10]. A method to generate heat using conductive yarns to present warmth has also been devised [8,11]. The existing methods have advantages and disadvantages in terms of stimulation parameters such as stimulation frequency, stimulation intensity, stimulation area, location, and response time depending on the source of actuation, but only one of the three tactile sensations, vibration, pressure, and warmth, can be presented by each actuator. A study that presents two types of sensations simultaneously has been carried out using electromagnetic coils and pneumatics to present vibration and pressure [12,13] or thermal fabric with continuous convexity using active material to present warmth and pressure [11,14]. A study to present three types of tactile sensations was attempted relatively recently. Pneumatic technology was used to present pressure and vibration sensations, and thermal fabric was used to present thermal sensations. However, it was difficult to achieve subtle intensities and high-frequency vibrations. Additionally, since the fabric, along with the pneumatic chamber, completely surrounded the fingertips, pressure and thermal sensations were presented not only on the lower part but also on the upper part of the fingers.