Printing electrodes for P(VDF-TrFE-CTFE) actuators using a consumer grade inkjet printer

Abstract

To facilitate smart material transducer research and application, it is important to develop fabrication processes that are widely accessible and compatible with additive manufacturing (AM) techniques. This work addresses inkjet printing and material selection in the fabrication of bending cantilever actuators based on the P(VDF-TrFE-CTFE) relaxor ferroelectric polymer. It investigates the effects of three different substrates (PEN, polyimide and a PET-based) and four different conductive inks (metal- and carbon-based) on the actuator fabrication and performance, to minimize process complexity and need for specialized equipment. First, electrode samples are manufactured for the feasible substrate-ink combination, their sheet resistances are measured, and their feasibility for actuator electrodes is analysed. Then, the simplest viable process is employed to fabricate the actuator samples, and their performance is measured in quasi-static and dynamic experiments. The least complex fabrication process was achieved with the resin-coated PET substrate (IJ-220) and carbon black electrodes (JR-700LV), only requiring a consumer-grade inkjet printer, a spin-coater and a thermal oven. The electrode samples showed 2.29 · 10³ Ω/□ sheet resistance at 10 print repetitions, indicating an actuator’s electrical bandwidth of 9.36 kHz. The manufactured actuators achieved 206 µm tip deflections in response to 1 Hz 300 V excitation, and up to 3 mm deflections in resonant operation at 115 Hz. Therefore, manufacturing flexible designs of well-performing smart material actuators is viable using widely available and low-budget equipment.