The Use of Color Indicators for Plasma Enhanced Chemical Vapor

Deposition (PECVD) Films

Brian LopasPhysics Teacher

Navasota High School, Navasota ISDDavid Staack, Ph.D.

Assistant Professor Department of Mechanical Engineering

Tsung-Chan “Cliff” TsaiDr. David Staack

Plasma Engineering and Diagnostics Laboratory

4th state of matter: ionized gas

Made of freely moving electrons and ions

Electrically charged particles that respond to electric and magnetic fields

Most abundant in the cosmos

What is plasma?

High temp electrons (20000 °F)Cold neutral gas – safe to touch

Examples:

Natural: Aurora borealis Artificial: Fluorescent lamp

Non-Thermal “Cold” Plasma

Non-Thermal “Cold” Plasma

Plasma Enhanced Chemical Vapor Deposition (PECVD)

Characteristics:• Non-thermal plasma• Adhesive to varies surfaces• Sterilizer

MMA

Floating substrate

HV

Power Supply

Helium

+-

--

-- -

- - -- -

- --

++

+ + ++ +

+++- - -

-

-

Electrode

Dielectric tube Plasma jet

* **

* *

*

**

*

Film (PMMA)

ApplicationsSuitable for live tissues◦Polymeric bandage on wounds◦Sterilizes

Research QuestionWhat indicator would be suitable to use under

PECVD conditions that would produce a colored film?

Equipment Setup

Color Indicator

Setup

Flow Controllers

Power Supply

Multimeter

Substrate(film produced here)

Bubbler (MMA) Plasma Jet

ExperimentsSolubility of methyl blue on MMAStability of methyl blue after plasma ejectionCondition of power supply (i.e. voltage, frequency, etc)Functionality of methyl blue on PMMA

If it works…Test other color indicators ◦methyl red◦bromothymol blue

Data generatedConditions to incorporate color indicator onto the

film◦Color indicator solvent/concentration◦Voltage◦Frequency of electricity◦Power◦Line spectra

Color indication

Why a color film?pH sensitivity of the film

Ability to indicate chemical/metabolic changes or re-infection

SummaryUse of low temperature plasma to deposit a film

Film is functional band-aid: compatible with live tissues, sterilizes and protects from re-infection

Film could indicate chemical/metabolic changes or re-infection

AcknowledgementsDr. David StaackTsung-Chan “Cliff” TsaiTexas A&M UniversityMechanical Engineering Department◦Plasma Engineering and Diagnostics Laboratory

National Science Foundation (NSF)Enrichment Experience in Engineering (E3)

Questions?