An electret power generator is developed using a new electret made of a charged parylene HT R thin-film polymer. Here, parylene HT R is a room-temperature chemical-vapor-deposited thin-film polymer that is MEMS and CMOS compatible. With corona charge implantation, the surface charge density of parylene HT R is measured as high as 3.69 mC m −2 . Moreover, it is found that, with annealing at 400• C for 1 h before charge implantation, both the long-term stability and the high-temperature reliability of the electret are improved. For the generator, a new design of the stator/rotor is also developed. The new micro electret generator does not require any sophisticated gap-controlling structure such as tethers. With the conformal coating capability of parylene HT R , it is also feasible to have the electret on the rotors, which is made of either a piece of metal or an insulator. The maximum power output, 17.98 μW, is obtained at 50 Hz with an external load of 80 M . For low frequencies, the generator can harvest 7.7 μW at 10 Hz and 8.23 μW at 20 Hz.

Abstract-We present a simple method to characterize parylene as a water barrier for soaking tests. The key component is the buried-in pentacene moisture sensor, which is a thin-film transistor sandwiched between two layers of parylene C. This pentacene thin-film transistor takes bottom contact configuration and uses parylene C as the gate dielectric material. Parylene films containing pentacene moisture sensors are soaked in saline at room temperature and the saturation drain current of pentacene thin film transistors is monitored. Hole mobility of pentacene is extracted via linearization of the square root of the drain current of the transistor versus gate voltages. We can determine the capability of parylene as a water permeation barrier by the changes of pentacene mobility.

We developed a novel, yet simple, micro electret power generator prototype for low-frequency energy harvesting applications. In this prototype, two electrodes of the power generator are placed on the stator. The rotor is only a plate with metal strips of half of the spatial frequency of the stator plate. The packaging is to simply fix the stator to a container and put the rotor directly on top of the stator. CYTOP, a MEMS-compatible perfluoropolymer, served as the electret material and charged with corona charging. The power output was 2.267μW at 60Hz.

A micro-fabricated parylene-packaged flexible pentacene thin film transistor is presented. Different from preceding devices that have been reported, this thin film transistor employs parylene as the substrate, the gate insulator and also the encapsulation layer. Also, this thin film transistor uses pentacene, an organic semiconductor with high mobility, as the active material. The transistor consists of Au/Cr gates and Au source and drain electrodes and takes a bottom-contact configuration. The freshly made thin film transistor shows a hole mobility of 0.084809 cm2/V-s with an on-off ratio of 104.

A micro-fabricated parylene-packaged flexible pentacene thin film transistor is presented. Different from preceding devices that have been reported, this thin film transistor employs parylene as the substrate, the gate insulator and also the top protection layer. Also, this thin film transistor uses pentacene, an organic semiconductor with high mobility, as the active material. The fresh made thin film transistor shows a hole mobility of 0.022 cm2/V-s. In spite of initial drops, the transistor's hole mobility stays at 0.001 cm2/V-s after over 6-month soaking in saline. We can conclude that drifts in mobility from soaking do exist but they saturate to values still of promise In addition, we believe there's plenty of room to improve the parylene packaging such as by using thicker parylene (this work used only 1 ptm).