Flexible Parylene-C Material and Its Applications in MOSFETs, RRAMs, and Sensors

Neuronal patterning on microfabricated architectures has developed rapidly over the past few years, together with the emergence of soft biocompatible materials and tissue engineering scaffolds. Previously, we introduced a patterning technique based on serum and the biopolymer parylene-C, achieving highly compliant growth of primary neurons and astrocytes on different geometries. Here, we expanded this technique and illustrated that neuralized cells derived from mouse embryonic stem cells (mESCs) followed stripes of variable widths with conformity equal to or higher than that of primary neurons and astrocytes. Our results indicate the presence of undifferentiated mESCs, which also conformed to the underlying patterns to a high degree. This is an exciting and unexpected outcome, as molecular mechanisms governing cell and ECM protein interactions are different in stem cells and primary cells. Our study enables further investigations into the development and electrophysiology of differentiating patterned neural stem cells.

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Structural Reinforcement Effect of a Flexible Strain Sensor Integrated with Pneumatic Balloon Actuators for Soft Microrobot Fingers

Micromachines ◽

10.3390/mi12040395 ◽

2021 ◽

Vol 12 (4) ◽

pp. 395

Author(s):

Satoshi Konishi ◽

Fuminari Mori ◽

Ayano Shimizu ◽

Akiya Hirata

Keyword(s):

Liquid Metal ◽

Strain Sensor ◽

Strain Sensors ◽

Original Performance ◽

Sensors And Actuators ◽

Parylene C ◽

Structural Reinforcement ◽

Effective Combination ◽

Metal Strain ◽

Flexible Strain Sensor

Motion capture of a robot and tactile sensing for a robot require sensors. Strain sensors are used to detect bending deformation of the robot finger and to sense the force from an object. It is important to introduce sensors in effective combination with actuators without affecting the original performance of the robot. We are interested in the improvement of flexible strain sensors integrated into soft microrobot fingers using a pneumatic balloon actuator (PBA). A strain sensor using a microchannel filled with liquid metal was developed for soft PBAs by considering the compatibility of sensors and actuators. Inflatable deformation generated by PBAs, however, was found to affect sensor characteristics. This paper presents structural reinforcement of a liquid metal-based sensor to solve this problem. Parylene C film was deposited into a microchannel to reinforce its structure against the inflatable deformation caused by a PBA. Parylene C deposition into a microchannel suppressed the interference of inflatable deformation. The proposed method enables the effective combination of soft PBAs and a flexible liquid metal strain sensor for use in microrobot fingers.

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All-Organic, Low Voltage, Transparent and Compliant Organic Field-Effect Transistor Fabricated by Means of Large-Area, Cost-Effective Techniques

Applied Sciences ◽

10.3390/app10196656 ◽

2020 ◽

Vol 10 (19) ◽

pp. 6656

Author(s):

Stefano Lai ◽

Giulia Casula ◽

Pier Carlo Ricci ◽

Piero Cosseddu ◽

Annalisa Bonfiglio

Keyword(s):

Field Effect ◽

Low Voltage ◽

Field Effect Transistors ◽

High Mobility ◽

Chemical Vapor ◽

Cost Effective ◽

Large Area ◽

Parylene C ◽

Biomedical Sensing ◽

Novel Applications

The development of electronic devices with enhanced properties of transparency and conformability is of high interest for the development of novel applications in the field of bioelectronics and biomedical sensing. Here, a fabrication process for all organic Organic Field-Effect Transistors (OFETs) by means of large-area, cost-effective techniques such as inkjet printing and chemical vapor deposition is reported. The fabricated device can operate at low voltages (as high as 4 V) with ideal electronic characteristics, including low threshold voltage, relatively high mobility and low subthreshold voltages. The employment of organic materials such as Parylene C, PEDOT:PSS and 6,13-Bis(triisopropylsilylethynyl)pentacene (TIPS pentacene) helps to obtain highly transparent transistors, with a relative transmittance exceeding 80%. Interestingly enough, the proposed process can be reliably employed for OFET fabrication over different kind of substrates, ranging from transparent, flexible but relatively thick polyethylene terephthalate (PET) substrates to transparent, 700-nm-thick, compliant Parylene C films. OFETs fabricated on such sub-micrometrical substrates maintain their functionality after being transferred onto complex surfaces, such as human skin and wearable items. To this aim, the electrical and electromechanical stability of proposed devices will be discussed.

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