Morphing wing technologies provide expanded functionality in piloted and robotic aircraft, extending particular vehicle mission parameters as well as increasing the role of aviation in both military and civilian applications. However, realizing control surfaces that do not void the benefits of morphing wings presents challenges that can be addressed with microfiber composite actuators (MFCs). We present two approaches for realizing control surfaces. In one approach, flap-like structures are formed by bonding MFCs to each side of a metal substrate. In the other approach, MFCs are bonded directly to the wing. Counter intuitively, the flap approach resulted in larger voltage actuation curvatures, with increased mass load. Actuation performance, defined as the ratio of curvature per applied voltage, was as large as (kV·mm)？1. The direct bonding approach reveals that at zero wing pressure, up to ？μm of displacement could be realized. 1. Introduction Traditional piezoelectric actuators, often referred to as “stack” actuators, have been used in numerous applications, including aeronautical applications [1, 2]. Traditional piezoelectric actuators are typically capable of exerting high pressures, but with small strains. This has limited their applicability. Newer actuator designs overcome the limitations of small displacements typical of traditional piezoelectric actuators by trading the characteristic high pressures for larger displacements. This is usually accomplished through various composite structures rather than expensive, high precision micromachined leveraging designs. Some of these newer composite actuator designs include Moonies [3], Rainbow [4], THUNDER [5], LIPCA [6], ECLIPSE [7], and MFCs [8]. Although several actuators show promise in other applications, micro-robotics [9]; for example, MFCs were chosen for this application because they are more flexible. In addition, they have been used in other aeronautical applications [10, 11]. A review of morphing aircraft can be found in [12]. The MFC actuators are formed by sandwiching piezoelectric fibers between polyimide layers. The polyimide layers have interdigitated electrodes that are a key feature of MFCs. They allow the utilization of the higher d33 piezoelectric coupling constants rather than the lower transverse d31 coupling constant. The high dielectric constant of the piezoelectric fiber concentrates, or condenses, the applied electric field inside the ceramic. More detailed information about MFCs can be found in the literature [8, 13, 14]. In this study we focus on an important aeronautical
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