Methods, systems, and devices are disclosed for monitoring the dispensing of a fluid from a container. In one aspect, a system includes a conformal substrate including a mechanically flexible and an electrically insulative material, the substrate attached and conformed to a container containing a fluid； a data acquisition unit including a sensor and a signal processing circuit formed on the conformal substrate, in which the sensor transduces an occurrence of the fluid dispensing from the container into an electrical signal, and the signal processing circuit amplifies the electrical signal； a data processing unit formed on the conformal substrate and in communication with the data acquisition unit to process the amplified electrical signal as data； and a communications unit formed on the conformal substrate and in communication with the data processing unit to wirelessly transmit the processed data to a remote device.
