A microneedle or microneedle device includes a microneedle body extending from a base to a penetrating tip formed from a silk fibroin based material, which is easy to fabricate and highly biocompatible. The microneedle device can include one or more microneedles mounted to a substrate. The silk fibroin can include active agents to be transported into or across biological barriers such as skin, tissue and cell membranes. The silk fibroin microneedles can be fully or partially biodegradable and/or bioerodible. The silk fibroin is highly stable, affords room temperature storage and is implantable. The silk fibroin structure can be modulated to control the rate of active agent delivery.