Liquid Metal Strain Gage to Test Cervical Facet Capsule Strain

A broad range of investigations has been carried out to suggest that the facet joint capsule is a source of neck pain and the pain may arise from large strain in the cervical facet capsule that will cause pain receptors to fire. So far, no direct methods to in vivo test the cervical facet capsule strain during rearend crashes have been known. To solve this methodology problem, a special liquid metal was selected as a sensing element to develop a miniature wire high-range strain gage. The calibration tests and a sled rear-end impact experiment were carried out to examine the technical behavior of this strain gage. It is shown that: This strain gage has a relatively high strain range and a relatively high degree of linearity. Due to a miniature wire structure and a relatively high degree of flexibility of use as well as a minimal external adhesive force, this strain gage has the capability of in vivo testing cervical facet capsule strain. In summary, this strain gage has a potential to become the first application research of liquid metal strain gage in testing cervical facet capsule strain during rear-end crashes.