The disclosure provides compositions that include microparticles or nanoparticles of beta inulin or inulin acetate and an active agent, where the active agent is contained within individual microparticles or nanoparticles. The material may be prepared by, for instance, casting an aqueous solution of domesticated silkworm silk fibroin on the surface of a substrate and then cast drying the applied solution. At this point, the delay time in the plurality of signal delaying means are set by time varying means based on the operational speed of a digital circuit which outputs digital data as the rectangular wave signals. The internal timer includes an oscillator formed of a plurality of inverters connected in ring shape and a variable capacitance circuit for each inverter.