Generating tactile sensation in mid-air has been widely demonstrated using an array of bulk piezoelectric transducers [1], [2]. Recently, micromachined devices have shown to be a valid alternative for this application [3], providing advantages in terms of form factor, resolution, ease of integration with supporting electronics and robustness. This paper describes the design of PMUT for short range mid-air haptic application. Circular PMUT and donut-shaped PMUT are investigated, and simulations are compared to measurements. Finally, a 1 by 1 cm silicon chip, containing 400um Aluminum Nitride PMUTs, is designed and characterized for delivering enough pressure to generate mid-air haptic feedback.