We present a compact broadband linear actuator, Chasm, that renders expressive haptic feedback on wearable and handheld devices. Unlike typical motor-based haptic devices with integrated gearheads, Chasm utilizes a miniature leadscrew coupled to a motor shaft, thereby directly translating the high-speed rotation of the motor to the linear motion of a nut carriage without an additional transmission. Due to this simplicity, Chasm can render low-frequency skin-stretch and high-frequency vibrations, simultaneously and independently. We present the design of the actuator assembly and validate its electromechanical and perceptual performance. We then explore use cases and show design solutions for embedding Chasm in device prototypes. Finally, we report investigations with Chasm in two VR embodiments, i.e., in a headgear band to induce locomotion cues and in a handheld pointer to enhance dynamic manual interactions. Our explorations show wide use for Chasm in enhancing user interactions and experience in virtual and augmented settings.