A micro-patterning technique regarded as micro transfer printing is studied for gold electrode patterning on cellulose electro-active paper (EAPap), aiming at biodegradable and flexible MEMS fabrication. EAPap is known as a smart material due to the interesting actuation phenomenon of cellulose paper. Accordingly, EAPap can be used for sensor and actuator devices. Since EAPap is made with cellulose, a biodegradable and flexible MEMS device can be made with this material. However, since cellulose-based EAPap is hydrophilic and flexible, conventional lithography and etching techniques cannot be used for micro-patterning. This paper reports a new micro-patterning technique using the micro transfer printing (MTP) method on flexible EAPap material. The MTP technique consists of a master fabrication, a polydimethylsiloxane (PDMS) stamp construction, and a micro pattern transfer. Details of the technique and key issues are addressed. To demonstrate the feasibility of the MTP technique, a gold electrode pattern for a surface acoustic wave (SAW) MEMS device and a gold micro-strip pattern for a microwave dipole rectenna are made on cellulose paper substrates.

Electro-Active Paper (EAPap) materials based on cellulose are attractive for many applications because of their low voltage operation, lightweight, dryness, low power consumption, bio-degradable. The construction of EAPap actuator has been achieved using the cellulose paper film coated with thin electrode layers. This actuator showed a reversible and reproducible bending movement. In order to improve both force and displacement of this, EAPap actuator efforts are made to construct the device using increasing number of complementary conducting polymer layers and carbon nanotubes. A hybrid EAPap actuator is developed using single-wall carbon nanotubes (CNT)/Polyaniline (PANi) electrodes, as a replacement to gold electrodes. It is expected that the use of CNT can enhance the stiffness of the tri-layered actuator, thus improving the force output. Furthermore, the presence of the CNT may increase the actuation performance of the EAPap material. CNT is dispersed in NMP(1-Methyl-2-pyrrolidine), and the resulting solution is used as a solvent for PANi. The CNT/PANi/NMP solution is then cast on the EAPap by spin coating. The coated EAPap is dried in an oven. The effect of processing parameters on the final performance of the CNT/PANi electrodes is assessed. The final performance of the electrodes is quantified in terms of the electrical conductivity under dc and ac measurement conditions. The actuation output of the CNT/PANi/EAPap samples is tested in an environmental chamber in terms of free displacement and blocked force. The performance of the hybrid actuators is also investigated in terms of frequency, voltage, humidity and temperature to help shed light on the mechanism responsible for actuation. Comparison of these results in that of the EAPap with PANi and gold electrodes are also accomplished. EAPap materials are bio-degradable that is important property for artificial muscle actuators for biomimetic with controlled properties and shape.

Electro-Active Paper (EAPap) is attractive as an EAP actuator material due to its merits in terms of lightweight, dry condition, large displacement output, low actuation voltage and low power consumption. This paper presents the fabrication and performance test of EAPap actuators. EAPap material has been made from cellulose materials. Cellulose fiber is dissolved into a solution and made into a sheet by using a spin coater. Thin electrodes are deposited on the cellophane sheet to comprise an EAPap. Next the EAPap is made into plate or beam specimens cut along a specific orientation to enhance the actuator performance. The EAPap is clamped on electric power connector and placed in an environmental chamber and the tip displacement of EAPap is measured with laser sensor. Also the blocking force of EAPap sample is measured. The measured force is compared with a theoretical beam model. These measurements are performed under a variety of environmental and input factors including frequency, actuation voltage, temperature and humidity. Characteristics of EAPap in terms of fibrous nature, their crystallinity, and mechanical, physical and electrochemical characteristics are presented.

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