The development of grasping is an important milestone that infants encounter during the first months of life. Novel approaches for measuring infants' manual actions are based on sensorized platform usable in natural settings, such as instrumented wireless toys that could be exploited for diagnosis and rehabilitation purposes. A new sensorized wireless toy has been designed and developed with embedded pressure sensors and audio-visual feedback. The fulfillment of clinical specifications has been proved through mechanical and electrical characterization. Infants showed a good grade of acceptance to such kind of tools, as confirmed by the results of preliminary tests that involved nine healthy infants: the dimensions fulfill infants' anthropometrics, the device is robust and safe, the acquired signals are in the expected range and the wireless communication is stable. Although achieved only through preliminary tests, such results confirm the hypothesis that this typology of instrumented toys could be useful for quantitative monitoring and measuring infants' motor development and ready to be evaluated for assessing motor skills through appropriate clinical trials.