Abstract: Opioids can be detected using a test system with ZnO pillars arranged in an array on a silicon wafer. Silver particles are on a top surface and/or side surface of the ZnO pillars. A sample fluid is applied to the test system. A concentration of an opioid compound in the sample fluid is determined using Surface-Enhanced Raman Spectroscopy of the test system. The sample fluid can be blood or a fluid isolated from blood.

Abstract: An electrostatic actuator has a first polymeric layer formed with an arch, a first electrode of metal deposited upon the first polymeric layer; a second polymeric layer formed flat; a second electrode of metal deposited upon the second polymeric layer; and a dielectric disposed on the second electrode. The second polymeric layer is mechanically coupled to the first polymeric layer at a first and second end of the arch. In an embodiment, the actuator has a pair of legs attached to the arch of the first polymeric layer to form a crawler unit. In another embodiment a steerable robot has a first crawling unit with its second polymeric layer mechanically coupled to the second polymeric layer of a second crawling unit.