摘要:
An electrical device is made by partially pyrolyzing polymer material by heating the material to between 500.degree. C. and 800.degree. C. Electrodes are applied to the material at two different locations to define an electrically active element therebetween. The device exhibits negative resistance in a portion of its voltage current domain and function as bi-directional electrical switches.This application is a continuation of application Ser. No. 859,709, filed May 5, 1986, now abandoned, which is a divisional application of application ser. No. 487,401, filed Apr. 21, 1983, now U.S. Pat. No. 4,642,644.