## 1 Introduction  
Virtual reality (VR) enables users to experience real events without actually being in the situation [1]. The core enabling technology for VR is software and hardware components for synthesizing appropriate physical signals for our five senses, which mimics the signals generated during real interactions. Due to recent advances in computer graphics and immersive visual display technology, the fidelity of visual feedback is reaching the level of the Turing test where a normal human can hardly distinguish between real and synthesized scenes [2]. The fidelity of haptic feedback, however, is still quite inferior to that of visual feedback in most VR systems [3], which is one of the areas that needs a technological breakthrough in VR [4]. Tactile feedback is one of the inevitable haptic modalities that can recreate the sense of touch. It provides the perception of pressure, vibration, and shear force [3]. Usual haptic interaction involves all types of tactile sensations, and thus, a haptic system should provide different tactile sensations for high-fidelity virtual interaction. However, most existing tactile actuators are operated based on electromagnetic principles [5, 6], and the feedback is rendered using pin arrays, voice coil actuators, linear resonant actuators, push-pull solenoid valves, etc. [7, 8]. Tactile sensations can be easily perceived using small actuators that are feasible to attach to and carry on the user's body [5]. However, the main drawback of these devices is that they can render only a single kind of feedback using a single module. Integrating multiple actuators can be a straightforward solution to overcome this issue. However, using multiple actuators can make the system heavy and limit usability, notably when wearability is the foremost concern. A multi-mode haptic actuator can be a solution to overcome the aforementioned issue. It has already been proven that a pneumatically controlled soft actuator can provide high-frequency vibrotactile feedback and pressure feedback with a single actuator [9]. Furthermore, it offers various functional advantages, which include lightweightness, flexibility, high strain density, and ease of fabrication as per the desired shape [10; 11]. It also performs a significant role in robotics, medical training, and telerobotics. [PERSON] et al [12] developed a soft pneumatic active actuator to mimic human sphincter muscles and simulate various anal sphincter tones for medical training. However, the main drawback of these works is that they rendered one kind of feedback at a time due to a simplified design, i.e., the single bladder design of the end effector. To overcome this issue, in this paper, we propose a dual-layer silicone-made fingertip actuator that provides both vibrotactile feedback and pressure feedback simultaneously. The proposed actuator consists of dual air chambers stacked on each another. The top/upper air chamber generates vibrotactile feedback, whereas the bottom/lower air chamber produces pressure feedback. The actuator was designed considering the shape of the users' fingertips having an average thickness so that it can be easily wearable on the index finger of the users. Although different fingertip sizes may affect the result of the experiment, it is manageable to construct new actuators of different sizes for users have diverse fingertip thicknesses. It lets the user direct contact at his/her fingers to minimize the constraint of hand movement [13]. The system renders realistic sensations with a pressure feedback of 5.5 N at 6 psi air pressure and 0.13 g vibration feedback along the z-axis. We further present a proof-of-concept rendering algorithm that shows the applicability of the new design. The major contributions of this work are summarized as follows.