|
1
|
Rommelfanger NJ, Brinson K, Bailey JE, Bancroft AM, Ou Z, Hong G. Pristine carbon nanotubes are efficient absorbers at radio frequencies. NANOTECHNOLOGY 2022; 33:10.1088/1361-6528/ac6cf8. [PMID: 35512668 PMCID: PMC9262147 DOI: 10.1088/1361-6528/ac6cf8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 05/04/2022] [Indexed: 05/19/2023]
Abstract
Radio frequency ablation and microwave hyperthermia are powerful tools for destroying dysfunctional biological tissues. However, wireless application of these techniques is hindered by their inability to focus the electromagnetic energy to small targets. The use of locally injected radio frequency- or microwave-absorbing nanomaterials can help to overcome this challenge by confining heat production to the injected region. Previous theoretical work suggests that high-aspect-ratio conducting nanomaterials, such as carbon nanotubes, offer powerful radio frequency and microwave absorption. While carbon nanotubes have been demonstrated as radiothermal agents, common solubilization methods may reduce their absorption efficiency, yielding undesirable nonspecific heating in the biological tissue background. In this manuscript, we hypothesize that pristine carbon nanotubes can act as efficient absorbers at radio frequencies, thus providing differential heating over the tissue background. Specifically, we use a sonication-free preparation technique to preserve both the high aspect ratio and local concentration of pristine carbon nanotubes. We validate the differential heating of these samples by 4.5-fold at 2 GHz compared to the heating of saline at a physiological concentration using infrared thermography. In addition, we successfully achieved local heating of pristine carbon nanotubes within a three-dimensional biological tissue phantom. Numerical simulations further aid in producing a temperature map within the phantom and confirming localized heating. Due to their significant differential and local heating, we believe that pristine carbon nanotubes may facilitate region-specific radio frequency ablation and microwave hyperthermia while keeping nonspecific heating to a low level in the normal tissue background.
Collapse
Affiliation(s)
- Nicholas J. Rommelfanger
- Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, 94305, USA
| | - Kenneth Brinson
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, 94305, USA
| | - John E. Bailey
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
- Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, 94305, USA
| | - Analiese M. Bancroft
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, 94305, USA
| | - Zihao Ou
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, 94305, USA
| | - Guosong Hong
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, 94305, USA
| |
Collapse
|
|
2
|
Guha S, Jamal FI, Wenger C. A Review on Passive and Integrated Near-Field Microwave Biosensors. BIOSENSORS-BASEL 2017; 7:bios7040042. [PMID: 28946617 PMCID: PMC5746765 DOI: 10.3390/bios7040042] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 09/07/2017] [Accepted: 09/21/2017] [Indexed: 11/16/2022]
Abstract
In this paper we review the advancement of passive and integrated microwave biosensors. The interaction of microwave with biological material is discussed in this paper. Passive microwave biosensors are microwave structures, which are fabricated on a substrate and are used for sensing biological materials. On the other hand, integrated biosensors are microwave structures fabricated in standard semiconductor technology platform (CMOS or BiCMOS). The CMOS or BiCMOS sensor technology offers a more compact sensing approach which has the potential in the future for point of care testing systems. Various applications of the passive and the integrated sensors have been discussed in this review paper.
Collapse
Affiliation(s)
- Subhajit Guha
- IHP, Im Technologiepark 25, 15236 Frankfurt (Oder), Germany.
| | | | | |
Collapse
|