Parylene-HT-based electret rotor generator

A new micro power generator with parylene HT electret rotor is made. This generator uses parylene HT as a new electret material with a much superior charge density compared to teflon and CYTOP. The highest surface potential observed is 204.58 V/mum, equivalent to a surface charge density of 3.69 mC/m^2. The generator uses an electret rotor. The rotor is a piece of PEEK insulator block coated with a layer of corona-charged parylene HT. Both output electrodes are on the stator. The generator produces 17.98 µW with 80MΩ load at 50Hz and 7.77 µW with an 800MΩ load at 10Hz

Parylene-based electret power generators

n electret power generator is developed using a new electret made of a charged parylene HT® thin-film polymer. Here, parylene HT® 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® 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®, 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 MΩ. For low frequencies, the generator can harvest 7.7 µW at 10 Hz and 8.23 µW at 20 Hz

A simple micro electret power generator

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

Recrystallized parylene as a mask for silicon chemical etching

This paper presents the first use of recrystallized parylene as masking material for silicon chemical etch. Recrystallized parylene was obtained by melting parylene C at 350°C for 2 hours. The masking ability of recrystallized parylene was tested in HNA (hydrofluoric acid, nitric acid and acetic acid) solution of various ratios, KOH (potassium hydroxide) solution and TMAH (tetramethylammonium hydroxide) at different temperatures and concentrations. It is found that interface between parylene and the substrate can be attacked, which results in undercuts. Otherwise, recrystallized parylene exhibited good adhesion to silicon, complete protection of unexposed silicon and silicon etching rates comparable to literature data

Performance of Parylene-Packaged Flexible Pentacene Thin-Film Transistors in Saline

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 cm^2/V-s. In spite of initial drops, the transistor's hole mobility stays at 0.001 cm^2/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 µm)

Design, Fabrication and Characterization of Parylene-Packaged Thin-Film Transistors

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 cm^2/V-s with an on-off ratio of 10^4

Design, Fabrication and Characterization of Parylene-Packaged Thin-Film Transistors

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 cm^2/V-s with an on-off ratio of 10^4

Characterization of Parylene as a Water Barrier via Buried-in Pentacene Moisture Sensors for Soaking Tests

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

Network Biology of Tumor Stem-like Cells Identified a Regulatory Role of CBX5 in Lung Cancer

Mounting evidence links cancers possessing stem-like properties with worse prognosis. Network biology with signal processing mechanics was explored here using expression profiles of a panel of tumor stem-like cells (TSLCs). The profiles were compared to their parental tumor cells (PTCs) and the human embryonic stem cells (hESCs), for the identification of gene chromobox homolog 5, CBX5, as a potential target for lung cancer. CBX5 was found to regulate the stem-like properties of lung TSLCs and was predictive of lung cancer prognosis. The investigation was facilitated by finding target genes based on modeling epistatic signaling mechanics via a predictive and scalable network-based survival model. Topologically-weighted measurements of CBX5 were synchronized with those of BIRC5, DNMT1, E2F1, ESR1, MLH1, MSH2, RB1, SMAD1 and TAF5. We validated our findings in another Taiwanese lung cancer cohort, as well as in knockdown experiments using sh-CBX5 RNAi both in vitro and in vivo.National Science Council (China) (NSC grant 100-2325-B-010-010-MY3/98-2314-B-010-024-MY2/97-3111-B075-001-MY3/ 96-2314-075-056-MY3)National Yang-Ming University (Ministry of Education, Aim for the Top University Plan: 96ADD122, 96ADD125, 96ADT191, 97ACD113, 97ACT302, 98ACT302, 98ACD107, 98ACT192 and Brain Research Center-3T-MRI project)))Taipei Veterans General Hospital (98-C1-099/E1-003/ER3-001)Taipei Veterans General Hospital (Joint Projects of VGHUST (98-G6-6/ 98-P1-01/99-P6-39)Chi Mei Medical Center (CMYM9801)Yen-Tjing-Ling Medical Foundation (96/97/98)Taipei City Hospital (96-002-62-092)Technology Development Program for Academia (TDPA; 98-EC-17-A-19-S2-0107)Taiwan. Department of Industrial Technology, Ministry of Economic AffairsNational Science Council (China) (NSC 101-2325-B-010 -009)Taiwan. Department of Health. Cancer Research Center of Excellence (DOH101-TD-C-111-007