Injectable depot compositions are provided that include a bioerodible, biocompatible polymer, a solvent having a miscibility in water of less than or equal to 7 wt. The hydrogel is conjugated with a multiphoton photocleavable molecule. Explosion type acoustical radiation may be used. An electrically conducting, thermally isolating anti-coupling layer, such as of gold or chromium, can reduce capacitive coupling between the thermally conductive structure and the thermometer element or other thermal sensor.