We are happy to introduce two new
wireless optogenetic stimulating systems:

• Smallest in the world battery-powered optogenetic stimulator
  Only 0.59 g including the battery and one light emitter. Ideal for small laboratory animals (mice, rats, etc.) The system is lightweight enough to be used with small songbirds (< 14 g body weight), such as zebra finches and canaries. Stimulator supports up to 4 independently controlled light emitting diodes (LEDs).
  
  
• Neurologger 2A/2B with integrated 4-channel optogenetic stimulator
  Following multiple requests we added wireless optogenetic stimulation to our popular logger of electrical brain activity Neurologger 2A/2B. Almost without weight increase the system allows recording of brain activity (4 channels up to 33 kHz sampling) together with activation or suppression of up to 4 brain areas by optogenetic tools. The system is designed for use with mice, rats and other laboratory animals.
  
  

Optogenetic stimulator capabilities

Stimulating capabilities of ultralight and integrated with Neurologger 2A/2B wireless optogenetic stimulators are similar. Key features are:

• High illuminating power. Even with the lightest battery peak LED input power ~1 W.
• Stable light output (accurate up to 1.5%). Light output does not degrade with battery discharge. It also does not depend on animal orientation and movements, contrary to systems exploiting energy harvesting.
• No potentially dangerous high-intensity electromagnetic waves like in energy-harvesting systems.
• Independent control of several stimulators attached to different animals in one environment.
• Reliable wireless connection between stationary controlling module and head-mounted stimulators. Direct transmitter-receiver visibility is not needed. Digital noise-free signal processing.
• Stimulating power is adjusted with 1% step.
• Continuous and pulse stimulation is possible. In pulse stimulation ON/OFF periods are adjusted in large ranges and with a small step.
• Power is adjusted in up to 4 channels individually and wirelessly in each stimulator.
• Individual ON/OFF control of up to 4 channels in each stimulator.
• Simple control from popular environments (Matlab, Python, LabView, etc.) through USB serial port emulation.
• Direct control through analog/digital input from other equipment.
  
  

Maximal duration of experiment with ultralight optogenetic stimulator

Longevity of experiments with batteries of different capacity and weight was estimated for ultralight single-channel optogenetic srtimulator in two modes:

• Waiting for incoming commands without stimulation.
• Optogenetic stimulation with 100 ms ON / 900 ms OFF schedule with 25% of maximal output power. This mode is depicted in photos and videos on this page.

Stimulator consumes 345 μA in waiting mode and on average 5.5 mA in stimulation mode (peak current 55 mA that is 25% of maximal current through 1 W peak power blue 460 nm LED with 3.7 V power supply).

Maximal duration of optogenetic stimulation with different batteries

Battery capacity (mAh)	Battery weight (g)	Total weight (g)	Duration of waiting mode (days)	Duration of stimulation (h)
12	0.36	0.59	1.45	2.18
20	0.63	0.86	2.42	3.64
40	1.05	1.28	4.83	7.27
50	1.58	1.81	6.04	9.09