Methods and devices for optoacoustic stimulation

A method of operating a tapered fiber optoacoustic emitter (TFOE)

• comprising:
• emitting laser pulses with a nanosecond laser and guiding the laser pulses with an optic fiber having a tip, the tip coated with a diffusion layer comprising epoxy and zinc oxide and a thermal expansion layer comprising carbon nanotubes (CNTs) and Polydimethylsiloxane (PDMS);
• diffusing the laser pulses while restricting localized heating, around the diffusion layer;
• converting the diffused light to generate ultrasound, with the thermal expansion layer;
• and
• tuning a frequency of the ultrasound based on a thickness of the diffusion layer and a CNT concentration in the expansion layer.

A tapered fiber optoacoustic emitter (TFOE), comprising:

• a nanosecond laser configured to emit laser pulses;
• and
• an optic fiber with a tip, the optic fiber configured to guide the laser pulses, the tip having a coating including a thermal expansion layer, wherein:
• the thermal expansion layer comprises carbon nanotubes (CNTs) and
• Polydimethylsiloxane (PDMS) configured to convert the laser pulses to generate ultrasound,
• wherein embedding CNT into a fibroin hydrogel forms an optoacoustic film, the fibroin hydrogel configured to stimulate neural growth in a subject in response to ultrasound;
• and
• the frequency of the ultrasound is tuned based on a thickness of the CNT concentration of the expansion layer.