## 1 Introduction  
In recent decades, technological advances in micro and nanotechnology have opened up new lines of research. The field of microrobotics has received great attention due to the possibility of manufacturing tiny devices, which offers many and diverse applications, mainly derived from the ability to access small spaces at the microscale. Concretely, tiny artificial devices propelled on liquid environments (TADPOLEs) can perform medical procedures in a minimally invasive way, deliver drugs with high precision, and detect towards diagnosis and monitoring, among other tasks [1, 2, 3, 4, 5, 6, 7, 8, 9]. However, the number of challenges increases as the working scale is scaled down, starting from fabrication techniques, power supply, as well as ways to propel such a kind of devices [6, 10, 11, 12, 13, 14, 15, 16, 17]. Therefore, a deep understanding of physics principles is fundamental for the design, manipulation, and control since the conventional consideration cannot be applied to the dynamic study of TADPOLEs: they have to work within environments characterized by a low Reynolds number (Re, which is a dimensionless parameter that quantifies the ratio between inertial and viscous forces in a fluid), i.e., within environments dominated by viscous forces. In this regime, the study of swimmers' dynamics acquires an important role in understanding the motion and finding new ways for propulsion. A review on the theoretical framework for locomotion at low Re can be found in [18, 19]. The analysis of the methods of propulsion at low Re inspired by biological systems has been extensively addressed in the literature from different perspectives. Considering only those focused on the well-known [PERSON]'s swimmers, approaches based on motion primitives and resistive forces were reported in [20; 21; 22; 23; 24]. Other approaches propose the generation of planar waves by means of an eukaryotic flagellum applying the following methods: (1) by active distributed actuation [25; 26; 27; 28]; (2) by two-point actuation [29; 30]; (3) by single-point actuation with the absorption of the reflected wave [29; 30]; and (4) by single-point actuation with a non-uniform distribution of mass (passive distributed actuation) [31; 32; 33]. However, the number of studies that analyze and implement these ways of propelling with a single material piece that can be found in the literature is limited. In this sense, the ionic polymer-metal composite (IPMC) is presented as an emerging material whose properties can fill this gap due to the possibility of both bending with a relatively low power supply (4-6 V) and underwater actuation, which makes it suitable for the development of swimming microrobots and biomedical applications. Nevertheless, the main works reported in robotics use IPMC as a simple actuator, with the robot body being made of other materials [34; 35; 36; 37; 38; 39]. On the other hand, working with IPMCs involves a great number of challenges, beginning with fabrication techniques, as well as behavior characterization and performance analysis for control, which requires understanding the physical models, as well as the influence of physical parameters [40; 41]. In this regard, different models describing the behavior of IPMC actuators have been reported, of integer [42] and non-integer orders consisting of two fractional poles and a fractional integrator [43]. In this context, this paper presents the first steps to propel a small-scale three-link artificial eukaryotic flagellum (AEF) swimming robot manufactured from a single IPMC sheet, where the three IPMC segments allow to actuate the flagellum in two ways: distributed, being the three segments active, or by single actuation, where only the first one is an actuator and the other two perform as passive links. Firstly, the robot modeling is addressed in the frequency domain to determine whether a single actuation is sufficient to generate a planar waveform, a motion that is necessary for robot propulsion in low Re.