Title

Development of Hydroxypropyl Cellulose and Polydimethylsiloxane Pressure Sensors

School Name

South Carolina Governor's School for Science and Mathematics

Grade Level

12th Grade

Presentation Topic

Engineering

Presentation Type

Mentored

Abstract

Hydroxypropyl cellulose (HPC) is a derivative of cellulose which, when mixed with water, will enter a liquid crystalline state. Liquid crystals (LCs) are materials with both conventional liquid and solid crystal behaviors. HPC in its LC state is responsive to pressure due to its helical structure. When the helix is compressed, the HPC will reflect shorter wavelengths of light, causing a blue-shift. The concentration of HPC and water must be in a specific range in order to exhibit this property, so when water evaporates, HPC becomes colorless. By encapsulating our HPC-water mixture inside a PDMS silicone film, we were able to prevent the water from evaporating and designed a functional pressure sensor. Further research with these sensors would likely include determining which wavelengths of light correspond with different amounts of pressure. Once that is determined, these sensors can be used for industrial and biomedical applications in the place of more expensive pressure sensing devices.

Location

HSS 113

Start Date

4-2-2022 9:30 AM

Presentation Format

Oral Only

Group Project

Yes

COinS
 
Apr 2nd, 9:30 AM

Development of Hydroxypropyl Cellulose and Polydimethylsiloxane Pressure Sensors

HSS 113

Hydroxypropyl cellulose (HPC) is a derivative of cellulose which, when mixed with water, will enter a liquid crystalline state. Liquid crystals (LCs) are materials with both conventional liquid and solid crystal behaviors. HPC in its LC state is responsive to pressure due to its helical structure. When the helix is compressed, the HPC will reflect shorter wavelengths of light, causing a blue-shift. The concentration of HPC and water must be in a specific range in order to exhibit this property, so when water evaporates, HPC becomes colorless. By encapsulating our HPC-water mixture inside a PDMS silicone film, we were able to prevent the water from evaporating and designed a functional pressure sensor. Further research with these sensors would likely include determining which wavelengths of light correspond with different amounts of pressure. Once that is determined, these sensors can be used for industrial and biomedical applications in the place of more expensive pressure sensing devices.