Yang, ChenCheng, Ji-XinXiang, Maijie2023-01-252023-01-252023https://hdl.handle.net/2144/45487High-precision neuromodulation with high efficacy poses great importance in neuroscience. Also, ultrasound frequency in sub-MHz gives greater penetration depth of neuromodulation in vivo, and has many different biomedical applications, such as ocular drug delivery, arte- rial hyperplasia reduction, etc. Here we fabricated a series of carbon-nanotube (CNT) and polydimethylsiloxane (PDMS) mixture films with different CNT concentration and thick- ness, which can generate highly efficient sub-MHz ultrasound. We discovered that 0.8% CNT concentration CNT/PDMS films gave approximately 1 MHz frequency, below which we achieved tunable frequency in sub-MHz area. Additionally, we adjusted the PDMS base to curing agent ratio and discovered that the 2:1 ratio’s optoacoustic conversion ef- ficiency is 1.6 times greater than the typical 10:1 ratio. Our work offers a potential way to increase photoacoustic conversion rate by optimizing CNT/PDMS films’ fabrication for further photoacoustic-related applications.en-USAttribution-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nd/4.0/NanoscienceThesis/Dissertation2023-01-170000-0001-8699-2642