Abstract:
The rapid development and commercial success of portable intelligent devices such as mobile phones, robotics, and wearable electronics has been defining future of the first decades of the 21st century. For these portable intelligent devices, polymers are attracting significant attention to make the products affordable, disposable and eco-friendly due to their unique properties. In this thesis, Polydimethysiloxane (PDMS), which is one of the most widely used polymers, will be explored. This thesis focuses on the novel applications of PDMS as resistive switching memory, low frequency vibration energy harvester, and skin force sensor. For the first time an optical polymer resistive memory using the unique blend of PDMS and gold nanoparticles has been demonstrated. This memory device is unique as it also demonstrated negative different resistance behaviour. In addition, a modified Simmons Verderber model has been established to explain the memory and negative differential resistance behaviours. Empirical models relating the PDMS mechanical properties to the curing parameters have been established through comprehensive design of experiment. Using these models a linear low frequency vibrational energy harvester has been demonstrated. Extending from this, a unique laminates of three PDMS layers with orthogonal stresses has been used to realise a non-linear structure, which can be accurately predicted using the model developed in this work and is capable of broadening the bandwidth from 2 Hz to 4 Hz. Finally, a skin force sensor consisting of a unique blend of conducting polymer PE- DOT:PSS with Arabitol as a piezoresistive sensing layer on a PDMS lm has been developed. This blend improves the conductivity and elasticity of the piezoresistive layer and has resulted with a sensor of a significant gauge factor of 11.5. In summary, the demonstration of these three unique applications using PDMS enables the realization of truly wearable, conformal, flexible and portable intelligent devices.