FAQs

• The array is ~20 um thick (in the z-direction).
• Depending on the array, the threads vary slightly in width (y-direction) but are ~250 um. 
• Depending on the array, the threads vary in length (x-direction) but range from ~3 cm - 8 cm. 
• Consult the Array Catalog for detailed specifications of each array.

The array’s design code is on the neck of the device which is visible under a microscope, as shown here.

• We offer 45 minute Zoom consultations to help users pick out types of arrays, discuss surgical implantations, and address any other questions or concerns users have. 
• The first shipment of arrays is free (for new users) and one can try a mix of array designs to test the various features and to see how they will work in your experimental paradigm.

Two main categories of paperwork are required (details are on the Myomatrix Procurement tab):

• Material transfer agreement (MTA) which sets up legal terms between Emory University and the receiving institution. The MTA requires the signature of the Principal Investigators and legal representatives for both Emory University and the receiving institution. 
• Setting up Emory-CAMBER as a vendor in your institution so that Emory can receive payment for the requested electrodes. The vendor setup varies from institution to institution and best to consult your procurement team for assistance in the setup. 

• If the arrays need to be fabricated, the typical wait time is ~ 6 weeks. 
• If arrays are in stock or in the fabrication cycle, the typical wait time is 3-4 weeks. Our team will communicate shipping information as the arrays advance through the fabrication cycle. 
• All shipments are sent via 2-day FEDEX.

All Myomatrix arrays and accessories are experimental devices and purchased as-is. While the arrays are quite robust, below are some handling recommendations when removing them from the shipping package. 

• Do not touch the electrode contacts (the blackish rectangles) or ground pad with forceps, as it is easy to damage these areas. 
• It is best to manipulate the arrays in the clear areas or by grasping the attached Omnetics connector. Don't grasp the electrode contacts as this risks damaging the PEDOT coating. 
• Avoid bending or kinking the array threads - both outside the surgery or in the animal. This can break the gold traces even if there is no visible breakage on the thread itself.
• The best practice is to impedance test all devices by 30 days after delivery and reach out to us at camber@emory.edu if the arrays appear faulty in some way. General impedance testing instructions can be found HERE. 

• Any standard 30g needle works well
• If your muscle target has significant fascia over it, best practice is to remove as much fascia as possible prior to array insertion. See the Tips and Tricks document for more information. 

• Use either 6.0, 8.0 or 10.0 sutures.
• The 6.0 suture needle will not fit through the suture holes but can be back threaded into the array.

• Do not autoclave any array with an attached Omnetics connector in a standard high heat and steam autoclave. 
• Arrays with the attached Omnetics connector can be sterilized in autoclaves using hydrogen peroxide gas plasma (similar to sterilizing sensitive medical tools). 
• A light spray of ethanol on the contracts is sufficient for acute preparations in animals. Do not spray ethanol on the Omnetic connector. 

• For arrays with attached Omnetics connectors, the contacts are on the same side as the connector. 
• The blacker, rougher side is the active contact; the smoother, shinier side is the polyimide. Observing the ground pad while magnified can help you learn to tell the difference and this information can be useful if the arrays get twisted when threading through the animal.

The 36-pin Omnetics connector plugs into a variety of headstages - the Sober lab generally uses the 16-channel bipolar headstage from Intan Technologies. Unipolar recordings are also an option; however, in our hands the on-chip subtraction via the bipolar headstage results in highest signal-to-noise ratio. 

The acquisition system is determined by the users’ needs and a non-exclusive list of options can be found at Getting Started>Tools and Hardware tab. 

• Grounding electrophysiological rigs can be more art than science so use whatever grounding system works best for your setup.
• The multiple threaded arrays have attached ground pads, which are best tucked under the animal’s skin at the nape of the neck. Arrays can be grounded to rigs, headbars, head screws, or other available options.

• The allowability of array re-use depends on compliance with applicable federal, state, and local regulations for animal or human subject research, as defined in the Material Transfer Agreement.
• The decision to re-use arrays depends on impedance values before and after use. If sufficient low-impedance contacts remain, arrays should be re-sterilized according to appropriate animal use protocols before re-use.
• Arrays placed on the muscle surface (rather than inserted) in acute preparations can generally be re-used multiple times if impedance values remain acceptable.

• Yes - In the Chung et al. (2023) ELife article, one can see an example of a recording from hawkmoth larva.  In addition, the CAMBER team has preliminary EMG data from recordings in stick insects and in locusts.
• For aquatic species, the challenge is to ensure the Omnetics connector and headstage are protected from water. If that issue is well-managed, one should be able to record from aquatic species. For example, users have successfully recorded from fixed zebrafish larvae.

• All Myomatrix arrays and accessories are experimental devices and purchased as-is.
• The best practice is to impedance test all devices within 30 days after delivery and reach out to us at camber@emory.edu if the arrays appear faulty in some way. General impedance testing instructions can be found HERE.